Amended and Restated Registration Rights Agreement, dated

This Amended and Restated Registration Rights Agreement (this “Agreement”) is made as of May 10, 2021 by and among Eos Energy Enterprises, Inc., a Delaware corporation (the “Company”), each of the other persons listed on the signature pages hereto (each, a “Securityholder” and collectively, the “Securityholders”), and any person or entity who hereafter becomes a party to this Agreement pursuant to Section 6.2 of this Agreement (together with the Securityholders and the RRA Parties (as defined below), each a “Holder” and, collectively, the “Holders”).

WHEREAS, the Registration Rights Agreeement dated as of November 16, 2020 was made and entered into in connection with the closing of the business combination (the “Business Combination”) by and among the Company and each of signatories thereto (the “RRA Parties”) contemplated by that certain Agreement and Plan of Merger, dated as of September 7, 2020 (the “Merger Agreement”), by and among BMRG Merger Sub, LLC, a Delaware limited liability company, BMRG Merger Sub II, LLC, a Delaware limited liability company, Eos Energy Storage LLC, a Delaware limited liability company, New Eos Energy LLC, a Delaware limited liability company, and AltEnergy Storage VI, LLC, a Delaware limited liability company (“AltEnergy Demanding Holder”), in its capacity as the Securityholder Representative thereunder;

WHEREAS, pursuant to the Merger Agreement, the Company issued to the Securityholders and other Holders shares of common stock of the Company, par value $0.0001 per share (the “Common Stock”), as consideration in the Business Combination;

WHEREAS, pursuant to the Merger Agreement, the Company agreed to register for resale under the Securities Act the shares of Common Stock issued to the Securityholders and other Holders; and

WHEREAS, the Company and the Holders desire to enter into this Agreement, pursuant to which the Company shall grant the Holders certain registration rights with respect to certain securities of the Company, and the parties hereto shall set forth their agreement with respect to certain other matters, as set forth in this Agreement.

NOW, THEREFORE, in consideration of the representations, covenants and agreements contained herein, and certain other good and valuable consideration, the receipt and sufficiency of which are hereby acknowledged, the parties hereto, intending to be legally bound, hereby agree as follows:

Section 1.1    Definitions. The terms defined in this Article I shall, for all purposes of this Agreement, have the respective meanings set forth below:

“Adverse Disclosure” shall mean any public disclosure of material non-public information, which disclosure, in the good faith judgment of the Chief Executive Officer or principal financial officer of the Company (if not Joe Mastrangelo), after consultation with counsel to the Company, (a) would be required to be made in any Registration Statement or Prospectus in order for the applicable Registration Statement or Prospectus not to contain any untrue statement of a material fact or omit to state a material fact necessary to make the statements contained therein (in the case of any prospectus and any preliminary prospectus, in the light of the circumstances under which they were made) not misleading, (b) would not be required to be made at such time if the Registration Statement were not being filed, and (c) the Company has a bona fide business purpose for not making such information public.

“Affiliate” shall mean, with respect to any specified Holder, any person or entity who directly or indirectly, controls, is controlled by or is under common control with such Holder, including, without limitation, any general partner, managing member, officer, director or trustee of such Holder, or any investment fund or registered investment company now or hereafter existing which is controlled by one or more general partners, managing members or investment advisers of, or shares the same management company or investment adviser with, such Holder.

“Agreement” shall have the meaning given in the Preamble.

“AltEnergy Demanding Holder” shall have the meaning given in the Recitals.

“Blackout Period” shall have the meaning given in Section 3.4(b).

“Business Combination” shall have the meaning given in the Preamble.

“Business Day” shall mean any day of the year on which national banking institutions in New York are open to the public for conducting business and are not required or authorized to close.

“Closing Date” shall have the meaning given in the Merger Agreement.

“Common Stock” shall have the meaning given in the Preamble.

“Commission” shall mean the U.S. Securities and Exchange Commission.

“Company” shall have the meaning given in the Preamble.

“Demanding Holder” shall have the meaning given in Section 2.2(a).

“Effectiveness Deadline” shall have the meaning given in Section 2.1.

“Exchange Act” shall mean the Securities Exchange Act of 1934, as it may be amended from time to time.

“Form S-3” shall have the meaning given in Section 2.4.

“Founder Holders” shall mean “Holders” as defined in the Founder Registration Rights Agreement.

“Founder Registrable Securities” shall mean “Registrable Securities” as defined in the Founder Registration Rights Agreement

“Founder Registration Rights Agreement” shall mean that certain Registration Rights Agreement, dated as of May 19, 2020, by and between the Company, B. Riley Principal Sponsor Co. II, LLC, a Delaware limited liability company, and the other parties thereto.

“Holders” shall have the meaning given in the Preamble.

“Lock-Up Period” shall mean the period ending on the earlier of (A) one year after the Closing Date or (B) subsequent to the Closing Date, (x) if the last sale price of the Common Stock equals or exceeds $12.00 per share (as adjusted for stock splits, stock dividends, reorganizations, recapitalizations and the like) for any 20 trading days within any 30-trading day period commencing at least 150 days after the Closing Date or (y) the date on which the Company completes a liquidation, merger, capital stock exchange, reorganization or other similar transaction that results in all of the Company’s stockholders having the right to exchange their shares of Common Stock for cash, securities or other property; provided, in the case of clause (B) (x), the Lock-up Period shall end no earlier than August 1, 2021.

“Maximum Number of Securities” shall have the meaning given in Section 2.2(b).

“Merger Agreement” shall have the meaning given in the Recitals.

“Misstatement” shall mean an untrue statement of a material fact or an omission to state a material fact required to be stated in a Registration Statement or Prospectus, or necessary to make the statements in a Registration Statement or Prospectus in the light of the circumstances under which they were made not misleading.

“MNPI” means material non-public information within the meaning of Regulation FD promulgated under the Exchange Act, which shall in any case include the receipt of any notice delivered by the Company under this Agreement, including pursuant to Article II hereof and the information contained in any such notice.

“Permitted Transferees” shall mean any person or entity to whom a Holder of Registrable Securities is permitted to transfer such Registrable Securities prior to the expiration of the Lock-up Period or any other lock-up period, as the case may be, under this Agreement and any other applicable agreement between such Holder and the Company, and to any transferee thereafter.

“Piggyback Registration” shall have the meaning given in Section 2.3.

“Prospectus” shall mean the prospectus included in any Registration Statement, as supplemented by any and all prospectus supplements and as amended by any and all post-effective amendments and including all material incorporated by reference in such prospectus.

“Registrable Security” shall mean (a) the shares of Common Stock issued by the Company to the Securityholders and any other Holders pursuant to the Merger Agreement and (b) any other equity security of the Company issued or issuable to any Holder with respect to any such shares of Common Stock by way of a stock dividend or stock split or in connection with a combination of shares, recapitalization, merger, consolidation or reorganization; provided,

however, that, as to any particular Registrable Security, such securities shall cease to be Registrable Securities when: (i) a Registration Statement with respect to the sale of such securities shall have become effective under the Securities Act and such securities shall have been sold, transferred, disposed of or exchanged in accordance with such Registration Statement; (ii) such securities shall have been otherwise transferred, new certificates for such securities not bearing a legend restricting further transfer shall have been delivered by the Company and subsequent public distribution of such securities shall not require registration under the Securities Act; (iii) such securities shall have ceased to be outstanding; (iv) such securities may be sold without registration pursuant to Rule 144 promulgated under the Securities Act (or any successor rule promulgated thereafter by the Commission) (but with no volume or other restrictions or limitations); or (v) such securities have been sold to, or through, a broker, dealer or underwriter in a public distribution or other public securities transaction.

“Registration” shall mean a registration effected by preparing and filing a registration statement or similar document in compliance with the requirements of the Securities Act, and the applicable rules and regulations promulgated thereunder, and such registration statement becoming effective.

“Registration Expenses” shall mean the out-of-pocket expenses of a Registration, including, without limitation, the following:

a.all registration and filing fees (including fees with respect to filings required to be             made with the Financial Industry Regulatory Authority, Inc.) and any securities exchange on which the Common Stock is then listed;

b.fees and expenses of compliance with securities or blue sky laws (including reasonable fees and disbursements of counsel for the Underwriters in connection with blue sky qualifications of Registrable Securities);

c.printing, messenger, telephone and delivery expenses;

d.reasonable fees and disbursements of counsel for the Company;

e.reasonable fees and disbursements of all independent registered public accountants of the Company incurred specifically in connection with such Registration (including the expenses of any special audit and “comfort letters” required by or incident to such performance); and

f.reasonable fees and expenses of one legal counsel selected by the Demanding Holders in connection with an Underwritten Offering.

“Registration Statement” shall mean any registration statement that covers the Registrable Securities pursuant to the provisions of this Agreement, including the Prospectus included in such registration statement, amendments (including post-effective amendments) and supplements to such registration statement, and all exhibits to and all material incorporated by reference in such registration statement.

“Securities Act” shall mean the Securities Act of 1933, as amended from time to time.

“Suspension Period” shall have the meaning given in Section 3.4(a).

“Transfer” shall mean the (a) sale of, offer to sell, contract or agreement to sell, hypothecate, pledge, grant of any option to purchase or otherwise dispose of or agreement to dispose of, directly or indirectly, or establishment or increase of a put equivalent position or liquidation with respect to or decrease of a call equivalent position within the meaning of Section 16 of the Exchange Act, and the rules and regulations of the Commission promulgated thereunder with respect to, any security, (b) entry into any swap or other arrangement that transfers to another, in whole or in part, any of the economic consequences of ownership of any security, whether any such transaction is to be settled by delivery of such securities, in cash or otherwise, or (c) public announcement of any intention to effect any transaction specified in clause (a) or (b).

“Underwriter” shall mean a securities dealer who purchases any Registrable Securities as principal in an Underwritten Offering and not as part of such dealer’s market-making activities.

“Underwritten Offering” shall mean an offering in which securities of the Company are sold to an Underwriter in a firm commitment underwriting for distribution to the public.

Section 2.1    Registration Statement. The Company shall, as soon as practicable after the Closing Date, but in any event within forty-five (45) days after the Closing Date, file a Registration Statement under the Securities Act to permit the public resale of all the Registrable Securities held by the Holders from time to time as permitted by Rule 415 under the Securities Act (or any successor or similar provision adopted by the Commission then in effect) on the terms and conditions specified in this Section 2.1 and shall use its commercially reasonable efforts to cause such Registration Statement to be declared effective as soon as practicable after the filing thereof, but in any event no later than the earlier of (a)  sixty (60) days (or ninety (90) days if the Commission notifies the Company that it will “review” the Registration Statement) after the Closing Date and (b) the tenth (10th) Business Day after the date the Company is notified (orally or in writing, whichever is earlier) by the Commission that such Registration Statement will not be “reviewed” or will not be subject to further review (such earlier date, the “Effectiveness Deadline”). The Registration Statement filed with the Commission pursuant to this Section 2.1 shall be on Form S-1 or such other form of registration statement as is then available to effect a registration for resale of such Registrable Securities, covering such Registrable Securities, and shall contain a Prospectus in such form as to permit any Holder to sell such Registrable Securities pursuant to Rule 415 under the Securities Act (or any successor or similar provision adopted by the Commission then in effect) at any time beginning on the effective date for such Registration Statement. A Registration Statement filed pursuant to this Section 2.1 shall provide for the resale pursuant to any method or combination of methods legally available to, and requested by, the Holders. The Company shall use its commercially reasonable efforts to cause a Registration Statement filed pursuant to this Section 2.1 to remain effective, and to be supplemented and amended to the extent necessary to ensure that such Registration Statement is available or, if not available, that another registration statement is available, for the resale of all the Registrable Securities held by the Holders until all such Registrable Securities have ceased to be Registrable Securities. As soon as practicable following the effective date of a Registration Statement filed pursuant to this Section 2.1, but in any event within three (3) Business Days of such date, the

Company shall notify the Holders of the effectiveness of such Registration Statement. When effective, a Registration Statement filed pursuant to this Section 2.1 (including any documents incorporated therein by reference) will comply as to form in all material respects with all applicable requirements of the Securities Act and the Exchange Act and will not contain an untrue statement of a material fact or omit to state a material fact required to be stated therein or necessary to make the statements therein not misleading (in the case of any Prospectus contained in such Registration Statement, in the light of the circumstances under which such statement is made).

a.In the event that any Holder elects to dispose of Registrable Securities under a Registration Statement pursuant to an Underwritten Offering of all or part of such Registrable Securities that are registered by such Registration Statement, then the Company shall, upon the written demand of AltEnergy Demanding Holder or its designee (any such Holder, a “Demanding Holder”), enter into an underwriting agreement in a form as is customary in Underwritten Offerings of equity securities with the managing Underwriter or Underwriters selected by the Demanding Holder in consultation with the Company, and shall take all such other reasonable actions as are requested by the managing Underwriter or Underwriters in order to expedite or facilitate the disposition of such Registrable Securities. Such underwriting agreement shall be satisfactory in form and substance to the Company and the Demanding Holder. In addition, the Company shall give prompt written notice to each other Holder regarding such proposed Underwritten Offering, and such notice shall offer such Holders the opportunity to include in the Underwritten Offering such number of Registrable Securities as each such Holder may request. Each such Holder shall make such request in writing to the Company within five Business Days after the receipt of any such notice from the Company, which request shall specify the number of Registrable Securities intended to be disposed of by such Holder.

b.If the managing Underwriter or Underwriters in an Underwritten Offering, in good faith, advises the Company and the Demanding Holder that the dollar amount or number of Registrable Securities that the Demanding Holder desires to sell, taken together with all other shares of Common Stock or other equity securities that the Company or any other Holder desires to sell and the shares of Common Stock, if any, as to which a Registration has been requested pursuant to separate written contractual piggy-back registration rights held by any other stockholders who desire to sell, exceeds the maximum dollar amount or maximum number of equity securities that can be sold in the Underwritten Offering without adversely affecting the proposed offering price, the timing, the distribution method, or the probability of success of such offering (such maximum dollar amount or maximum number of such securities, as applicable, the “Maximum Number of Securities”), then the Company shall include in such Underwritten Offering, as follows:

i.first, pro rata to (A) Registrable Securities of the Holders (including the Demanding Holders) who have elected to participate in the Underwritten Offering pursuant to Section 2.2(a) and (B)  Founder Registrable Securities of Founder Holders exercising their rights to register their Founder Registrable Securities pursuant to the

Founder Registration Rights Agreement, which can be sold without exceeding the Maximum Number of Securities;

ii.second, to the extent that the Maximum Number of Securities has not been reached under the foregoing clause (i), to shares of Common Stock held by persons or entities that the Company is obligated to register in a Registration pursuant to separate written contractual arrangements with such persons, which collectively can be sold without exceeding the Maximum Number of Securities; and

iii.third, to the extent that the Maximum Number of Securities has not been reached under the foregoing clause (i) or clause (ii), shares of Common Stock or other equity securities that the Company desires to sell, which can be sold without exceeding the Maximum Number of Securities.

c.A Demanding Holder shall have the right to withdraw all or any portion of its Registrable Securities included in an Underwritten Offering pursuant to this Section 2.2 for any or no reason whatsoever upon written notification to the Company and the Underwriter or Underwriters of its intention to withdraw from such Underwritten Offering prior to the pricing of such Underwritten Offering and such withdrawn amount shall no longer be considered an Underwritten Offering. Notwithstanding anything to the contrary in this Agreement, the Company shall be responsible for the Registration Expenses incurred in connection with an Underwritten Offering prior to its withdrawal under this Section 2.2(c).

d.The Company shall not be obligated to effect any Underwritten Offering pursuant to this Section 2.2 (x) if the Demanding Holder, together with the holders of any other securities of the Company entitled to inclusion in such Underwritten Offering, propose to sell Registrable Securities and such other securities (if any), the aggregate proceeds of which are anticipated to be less than $15,000,000, or (y) in any particular jurisdiction in which the Company would be required to execute a general consent to service of process in effecting such registration, qualification, or compliance, unless the Company is already subject to service in such jurisdiction and except as may be required by the Securities Act.

a.If at any time the Company proposes to file a Registration Statement under the Securities Act with respect to an Underwritten Offering of equity securities, or securities or other obligations exercisable or exchangeable for, or convertible into equity securities, for its own account or for the account of stockholders of the Company (or by the Company and by the stockholders of the Company including, without limitation, pursuant to Section 2.2 hereof) on a form that would permit registration of Registrable Securities, other than a Registration Statement (i) filed in connection with any employee stock option or other benefit plan, (ii) for an exchange offer or offering of securities solely to the Company’s existing stockholders, (iii) for an offering of debt that is convertible into equity securities of the Company, (iv) for a dividend reinvestment plan or (v) on Form S-4, then the Company shall give written notice of such proposed filing to all of the Holders of Registrable Securities as soon as practicable but not less than ten days before the anticipated filing date of such Registration Statement, which notice shall (A)  describe the

amount and type of securities to be included in such offering, the intended method(s) of distribution, and the name of the proposed managing Underwriter or Underwriters, if any, in such offering, and (B) offer to all of the Holders of Registrable Securities the opportunity to register the sale of such number of Registrable Securities as such Holders may request in writing within five days after receipt of such written notice (in the case of an “overnight” or “bought” offering, such requests must be made by the Holders within three Business Days after the delivery of any such notice by the Company) (such Registration a “Piggyback Registration”); provided, however, that if the Company has been advised in writing by the managing Underwriter(s) that the inclusion of Registrable Securities for sale for the benefit of the Holders will have an adverse effect on the price, timing or distribution of the Common Stock in the Underwritten Offering, then (1) if no Registrable Securities can be included in the Underwritten Offering in the opinion of the managing Underwriter(s), the Company shall not be required to offer such opportunity to the Holders or (2) if any Registrable Securities can be included in the Underwritten Offering in the opinion of the managing Underwriter(s), then the amount of Registrable Securities to be offered for the accounts of Holders shall be determined based on the provisions of Section 2.3(b). Subject to Section 2.3(b), the Company shall, in good faith, cause such Registrable Securities to be included in such Piggyback Registration and shall use its commercially reasonable efforts to cause the managing Underwriter or Underwriters of a proposed Underwritten Offering to permit the Registrable Securities requested by the Holders pursuant to this Section 2.3 to be included in a Piggyback Registration on the same terms and conditions as any similar securities of the Company included in such Registration and to permit the sale or other disposition of such Registrable Securities in accordance with the intended method(s) of distribution thereof. If no written request for inclusion from a Holder is received within the specified time, each such Holder shall have no further right to participate in such Underwritten Offering. All such Holders proposing to distribute their Registrable Securities through an Underwritten Offering under this Section 2.3 shall enter into an underwriting agreement in customary form with the Underwriter(s) selected for such Underwritten Offering by the Company.

b.If the managing Underwriter or Underwriters in an Underwritten Offering that is to be a Piggyback Registration, in good faith, advises the Company and the Holders of Registrable Securities participating in the Piggyback Registration in writing that the dollar amount or number of shares of Common Stock that the Company desires to sell, taken together with (i) the shares of Common Stock, if any, as to which Registration has been demanded pursuant to separate written contractual arrangements with persons or entities other than the Holders of Registrable Securities hereunder, (ii) the Registrable Securities as to which registration has been requested pursuant to Sections 2.2 and 2.3, and (iii) the shares of Common Stock, if any, as to which Registration has been requested pursuant to separate written contractual piggy-back registration rights of other stockholders of the Company, exceeds the Maximum Number of Securities, then:

i.If the Registration is undertaken for the Company’s account, the Company shall include in any such Registration (A) first, shares of Common Stock or other equity securities that the Company desires to sell, which can be sold without exceeding the Maximum Number of Securities; (B) second, to the extent that the Maximum Number of Securities has not been reached under the foregoing clause (A), pro

rata to (1) the Registrable Securities of Holders exercising their rights to register their Registrable Securities pursuant to Sections 2.2 and 2.3 hereof; and (2)  the Founder Registrable Securities of Founder Holders exercising their rights to register their Founder Registrable Securities pursuant to the Founder Registration Rights Agreement, which can be sold without exceeding the Maximum Number of Securities, and (C) third, to the extent that the Maximum Number of Securities has not been reached under the foregoing clauses (A) and (B), shares of Common Stock, if any, as to which Registration has been requested pursuant to written contractual piggy-back registration rights of other stockholders of the Company, which can be sold without exceeding the Maximum Number of Securities;

ii.If the Registration is pursuant to a request by persons or entities other than the Holders of Registrable Securities, then the Company shall include in any such Registration (A) first, shares of Common Stock or other equity securities, if any, of such requesting persons or entities, other than the Holders of Registrable Securities, which can be sold without exceeding the Maximum Number of Securities; (B) second, to the extent that the Maximum Number of Securities has not been reached under the foregoing clause (A), pro rata to (1) the Registrable Securities of Holders exercising their rights to register their Registrable Securities pursuant to Sections 2.2 and 2.3 hereof; and (2)  the Founder Registrable Securities of Founder Holders exercising their rights to register their Founder Registrable Securities pursuant to the Founder Registration Rights Agreement, which can be sold without exceeding the Maximum Number of Securities; (C) third, to the extent that the Maximum Number of Securities has not been reached under the foregoing clauses (A) and (B), shares of Common Stock or other equity securities that the Company desires to sell, which can be sold without exceeding the Maximum Number of Securities; and (D) fourth, to the extent that the Maximum Number of Securities has not been reached under the foregoing clauses (A), (B) and (C), shares of Common Stock or other equity securities for the account of other persons or entities that the Company is obligated to register pursuant to separate written contractual arrangements with such persons or entities, which can be sold without exceeding the Maximum Number of Securities.

c.Any Holder of Registrable Securities shall have the right to withdraw from a Piggyback Registration for any or no reason whatsoever upon written notification to the Company and the Underwriter or Underwriters (if any) of its intention to withdraw from such Piggyback Registration prior to the pricing of such Underwritten Offering. The Company (whether on its own good faith determination or as the result of a request for withdrawal by persons pursuant to separate written contractual obligations) may withdraw a Registration Statement filed with the Commission in connection with a Piggyback Registration at any time prior to the effectiveness of such Registration Statement. Notwithstanding anything to the contrary in this Agreement, the Company shall be responsible for the Registration Expenses incurred in connection with the Piggyback Registration prior to its withdrawal under this Section 2.3.

d.For purposes of clarity, any Registration effected pursuant to Section 2.3 hereof shall not be counted as a Registration effected under Section 2.2 hereof. In addition, no written notice of a Piggyback Registration expected to be consummated prior to the expiration of the applicable Lock-Up Period pursuant to Article V hereof shall be required to be delivered under this Section 2.3.

Section 2.4    Registrations on Form S-3. The Holders of Registrable Securities may at any time, and from time to time, request in writing that the Company, pursuant to Rule 415 under the Securities Act (or any successor rule promulgated thereafter by the Commission), register the resale of any or all of their Registrable Securities on Form S-3 or similar short form registration statement that may be available at such time (“Form S-3”); provided, however, that the Company shall not be obligated to effect such request through an Underwritten Offering. Within five days of the Company’s receipt of a written request from a Holder or Holders of Registrable Securities for a Registration on Form S-3, the Company shall promptly give written notice of the proposed Registration on Form S-3 to all other Holders of Registrable Securities, and each Holder of Registrable Securities who thereafter wishes to include all or a portion of such Holder’s Registrable Securities in such Registration on Form S-3 shall so notify the Company, in writing, within ten days after the receipt by the Holder of the notice from the Company. As soon as practicable thereafter, but not more than 12 days after the Company’s initial receipt of such written request for a Registration on Form S-3, the Company shall register all or such portion of such Holder’s Registrable Securities as are specified in such written request, together with all or such portion of Registrable Securities of any other Holder or Holders joining in such request as are specified in the written notification given by such Holder or Holders; provided, however, that the Company shall not be obligated to effect any such Registration pursuant to Section 2.3 hereof if (i) a Form S-3 is not available for such offering, or (ii) the Holders of Registrable Securities, together with the Holders of any other equity securities of the Company entitled to inclusion in such Registration, propose to sell the Registrable Securities and such other equity securities (if any) at any aggregate price to the public of less than $10,000,000.

Section 3.1    General Procedures. The Company shall use its commercially reasonable efforts to effect the Registration of Registrable Securities in accordance with the intended plan of distribution thereof, and pursuant thereto the Company shall, as expeditiously as practicable:

a.subject to Section 2.1, prepare and file with the Commission a Registration Statement with respect to such Registrable Securities and use its commercially reasonable efforts to cause such Registration Statement to become effective and remain effective pursuant to the terms of this Agreement until all of such Registrable Securities have been disposed of;

b.prepare and file with the Commission such amendments and post-effective amendments to the Registration Statement, and such supplements to the Prospectus, as may be required by the rules, regulations or instructions applicable to the registration form used by the Company or by the Securities Act or rules and regulations thereunder to keep the Registration Statement effective until all of such Registrable Securities have been disposed of in accordance

with the intended plan of distribution set forth in such Registration Statement or supplement to the Prospectus;

c.prior to filing a Registration Statement or Prospectus, or any amendment or supplement thereto, furnish without charge to the Underwriters, if any, and the Holders of Registrable Securities included in such Registration, and to one legal counsel selected by the Holders, copies of such Registration Statement as proposed to be filed, each amendment and supplement to such Registration Statement (in each case including all exhibits thereto and documents incorporated by reference therein), the Prospectus included in such Registration Statement (including each preliminary Prospectus), and such other documents as the Underwriters and the Holders of Registrable Securities included in such Registration or the legal counsel selected by such Holders may request in order to facilitate the disposition of the Registrable Securities owned by such Holders;

d.prior to any public offering of Registrable Securities, use its commercially reasonable efforts to (i) register or qualify the Registrable Securities covered by the Registration Statement under such securities or “blue sky” laws of such jurisdictions in the United States as the Holders of Registrable Securities included in such Registration Statement (in light of their intended plan of distribution) may request and (ii) take such action necessary to cause such Registrable Securities covered by the Registration Statement to be registered with or approved by such other governmental authorities as may be necessary by virtue of the business and operations of the Company and do any and all other acts and things that may be necessary or advisable to enable the Holders of Registrable Securities included in such Registration Statement to consummate the disposition of such Registrable Securities in such jurisdictions; provided, however, that the Company shall not be required to qualify generally to do business or as a dealer in securities in any jurisdiction where it would not otherwise be required to qualify or take any action to which it would be subject to general service of process or taxation in any such jurisdiction where it is not then otherwise so subject;

e.use its commercially reasonable efforts to cause all such Registrable Securities to be listed on each securities exchange or automated quotation system on which similar securities issued by the Company are then listed;

f.provide a transfer agent and registrar for all such Registrable Securities no later than the effective date of such Registration Statement;

g.advise each seller of such Registrable Securities, promptly after it shall receive notice or obtain knowledge thereof, of the issuance of any stop order by the Commission suspending the effectiveness of such Registration Statement or the initiation or threatening of any proceeding for such purpose and promptly use its commercially reasonable efforts to prevent the issuance of any stop order or to obtain its withdrawal if such stop order should be issued;

h.at least five days prior to the filing of any Registration Statement or Prospectus or any amendment or supplement to such Registration Statement or Prospectus or any document that is to be incorporated by reference into such Registration Statement or Prospectus, furnish a copy thereof to each seller of such Registrable Securities or its counsel;

i.notify the Holders at any time when a Prospectus relating to such Registration Statement is required to be delivered under the Securities Act, of the happening of any event as a result of which the Prospectus included in such Registration Statement, as then in effect, includes a Misstatement, and then to correct such Misstatement as set forth in Section 3.4 hereof;

j.permit a representative of the Holders, the Underwriters, if any, and any attorney or accountant retained by such Holders or Underwriter to participate, at each such person’s own expense, in the preparation of the Registration Statement, and cause the Company’s officers, directors and employees to supply all information reasonably requested by any such representative, Underwriter, attorney or accountant in connection with the Registration; provided, however, that such representatives or Underwriters enter into a confidentiality agreement, in form and substance reasonably satisfactory to the Company, prior to the release or disclosure of any such information;

k.obtain a “cold comfort” letter from the Company’s independent registered public accountants in the event of an Underwritten Offering, in customary form and covering such matters of the type customarily covered by “cold comfort” letters as the managing Underwriter may reasonably request;

l.on the date the Registrable Securities are delivered for sale pursuant to such Registration, obtain an opinion, dated as of such date, of counsel representing the Company for the purposes of such Registration, addressed to the placement agent or sales agent, if any, and the Underwriters, if any, covering such legal matters with respect to the Registration in respect of which such opinion is being given as are customarily included in such opinions and negative assurance letters;

m.in the event of any Underwritten Offering, enter into and perform its obligations under an underwriting agreement, on terms agreed to by the Company with the managing Underwriter of such offering;

n.make available to its security holders, as soon as reasonably practicable, an earnings statement (which need not be audited) covering the period of at least twelve (12) months beginning with the first day of the Company’s first full calendar quarter after the effective date of the Registration Statement which satisfies the provisions of Section 11(a) of the Securities Act and Rule 158 thereunder (or any successor rule promulgated thereafter by the Commission);

o.if the Registration involves the Registration of Registrable Securities involving gross proceeds in excess of $30,000,000, use its reasonable efforts to make available senior executives of the Company to participate in customary “road show” presentations that may be reasonably requested by the Underwriter in such Underwritten Offering; and

p.otherwise, in good faith, take such customary actions necessary to effect the registration of such Registrable Securities contemplated hereby.

Section 3.2    Registration Expenses. The Registration Expenses of all Registrations shall be borne by the Company. It is acknowledged by the Holders and the Company that the Holders

shall bear all incremental selling expenses relating to the sale of Registrable Securities, such as Underwriters’ commissions and discounts, brokerage fees and, other than as set forth in the definition of “Registration Expenses,” all reasonable fees and expenses of any legal counsel representing the Holders.

Section 3.3    Requirements for Participation in Underwritten Offerings. No person may participate in any Underwritten Offering for equity securities of the Company hereunder unless such person (a) agrees to sell such person’s securities on the basis provided in the underwriting agreement for such Underwritten Offering and (b) completes and executes all customary questionnaires, powers of attorney, indemnities, lock-up agreements, underwriting agreements and other customary documents as may be reasonably required under the terms of such underwriting agreement. Each Holder proposing to distribute its Registrable Securities through an Underwritten Offering for equity securities of the Company hereunder shall enter into an underwriting agreement with the underwriters, which underwriting agreement shall contain such representations, covenants, indemnities (subject to Article IV) and other rights and obligations as are customary in underwritten offerings of equity securities; provided, however, that no such Holder shall be required to make any representations or warranties to or agreements with the Company or the Underwriters other than representations, warranties or agreements regarding such Holder’s authority to enter into such underwriting agreement and to sell, and its ownership of, the securities being registered on its behalf, its intended method of distribution and any other representation required by law.

a.Upon receipt of written notice from the Company that a Registration Statement or Prospectus contains a Misstatement, each of the Holders shall forthwith discontinue disposition of Registrable Securities until it has received copies of a supplemented or amended Prospectus correcting the Misstatement (it being understood that the Company hereby covenants to prepare and file such supplement or amendment as soon as practicable after the time of such notice), or until it is advised in writing by the Company that the use of the Prospectus may be resumed (any such period, a “Suspension Period”).

b.If the filing, initial effectiveness or continued use of a Registration Statement in respect of any Registration (including in connection with an Underwritten Offering) at any time would require the Company to make an Adverse Disclosure or would require the inclusion in such Registration Statement of financial statements that are unavailable to the Company for reasons beyond the Company’s control, then the Company may, upon giving prompt written notice to the Holders, delay the filing or initial effectiveness of, or suspend use of, such Registration Statement (including in connection with an Underwritten Offering) for the shortest period of time, but in no event more than 30 days, determined in good faith by the Company to be necessary for such purpose (any such period, a “Blackout Period”). In the event the Company exercises its rights under the preceding sentence, the Holders agree to suspend, immediately upon their receipt of the notice referred to above, their use of the Prospectus relating to any Registration in connection with any sale or offer to sell Registrable Securities.

c.The Company shall immediately notify the Holders of the expiration of any period during which it exercised its rights under this Section 3.4. Notwithstanding anything to the

contrary in this Section 3.4, in no event shall any Suspension Period or any Blackout Period continue for more than 30 days in the aggregate during any 365-day period.

Section 3.5    Reporting Obligations. As long as any Holder shall own Registrable Securities, the Company, at all times while it shall be a reporting company under the Exchange Act, covenants to:

a.file timely (or obtain extensions in respect thereof and file within the applicable grace period) all reports required to be filed by the Company after the date hereof pursuant to Sections 13(a) or 15(d) of the Exchange Act and to promptly furnish the Holders with true and complete copies of all such filings (the delivery of which will be satisfied by the Company’s filing of such reports on the Commission’s EDGAR system); and

b.the Company further covenants that it shall take such further action as any Holder may reasonably request, all to the extent required from time to time to enable such Holder to sell shares of Common Stock held by such Holder without registration under the Securities Act within the limitation of the exemptions provided by Rule 144 promulgated under the Securities Act (or any successor rule promulgated thereafter by the Commission), including providing any legal opinions. Upon the request of any Holder, the Company shall deliver to such Holder a written certification of a duly authorized officer as to whether it has complied with such requirements.

a.The Company agrees to indemnify, to the extent permitted by law, each Holder of Registrable Securities, its officers and directors and each person who controls (within the meaning of the Securities Act) such Holder (and the directors and officers thereof) against all losses, claims, damages, liabilities and expenses (including attorneys’ fees) caused by any untrue or alleged untrue statement of material fact contained in any Registration Statement, Prospectus or preliminary Prospectus or any amendment thereof or supplement thereto or any omission or alleged omission of a material fact required to be stated therein or necessary to make the statements therein not misleading, except insofar as the same are caused by or contained in any information furnished in writing to the Company by such Holder expressly for use therein. The Company shall indemnify the Underwriters, their officers and directors and each person who controls such Underwriters (within the meaning of the Securities Act) to the same extent as provided in the foregoing with respect to the indemnification of the Holder.

b.In connection with any Registration Statement in which a Holder of Registrable Securities is participating, such Holder shall furnish to the Company in writing such information and affidavits as the Company reasonably requests for use in connection with any such Registration Statement or Prospectus and, to the extent permitted by law, shall indemnify the Company, its directors and officers and agents and each person who controls the Company

(within the meaning of the Securities Act) against any losses, claims, damages, liabilities and expenses (including without limitation reasonable attorneys’ fees) resulting from any untrue statement of material fact contained in the Registration Statement, Prospectus or preliminary Prospectus or any amendment thereof or supplement thereto or any omission of a material fact required to be stated therein or necessary to make the statements therein not misleading, but only to the extent that such untrue statement or omission is contained in any information or affidavit so furnished in writing by such Holder expressly for use therein; provided, however, that the obligation to indemnify shall be several, not joint and several, among such Holders of Registrable Securities, and the liability of each such Holder of Registrable Securities shall be in proportion to and limited to the net proceeds received by such Holder from the sale of Registrable Securities pursuant to such Registration Statement. The Holders of Registrable Securities shall indemnify the Underwriters, their officers, directors and each person who controls such Underwriters (within the meaning of the Securities Act) to the same extent as provided in the foregoing with respect to indemnification of the Company.

c.Any person entitled to indemnification herein shall (i) give prompt written notice to the indemnifying party of any claim with respect to which it seeks indemnification (provided that the failure to give prompt notice shall not impair any person’s right to indemnification hereunder to the extent such failure has not materially prejudiced the indemnifying party) and (ii) unless in such indemnified party’s reasonable judgment a conflict of interest between such indemnified and indemnifying parties may exist with respect to such claim, permit such indemnifying party to assume the defense of such claim with counsel reasonably satisfactory to the indemnified party. If such defense is assumed, the indemnifying party shall not be subject to any liability for any legal or other expenses subsequently incurred by such indemnified party in connection with the defense thereof (other than reasonable costs of investigation) or any settlement made by the indemnified party without its consent (but such consent shall not be unreasonably withheld); provided, however, that (x) if the indemnifying party fails to take reasonable steps necessary to defend diligently the action or proceeding within 20 days after receiving notice from such indemnified party, (y) if such indemnified party who is a defendant in any action or proceeding that is also brought against the indemnifying party reasonably shall have concluded that there may be one or more legal defenses available to such indemnified party that are not available to the indemnifying party or (z) if representation of both parties by the same counsel is otherwise inappropriate under applicable standards of professional conduct, then, in any such case, the indemnified party shall have the right to assume or continue its own defense and the indemnifying party shall be liable for any expenses therefor. An indemnifying party who is not entitled to, or elects not to, assume the defense of a claim shall not be obligated to pay the fees and expenses of more than one counsel for all parties indemnified by such indemnifying party with respect to such claim, unless in the reasonable judgment of any indemnified party a conflict of interest may exist between such indemnified party and any other of such indemnified parties with respect to such claim. No indemnifying party shall, without the consent of the indemnified party, consent to the entry of any judgment or enter into any settlement which cannot be settled in all respects by the payment of money (and such money is so paid by the indemnifying party pursuant to the terms of such settlement) or which settlement does not include as an unconditional term thereof the giving by the claimant or plaintiff to such indemnified party of a release from all liability in respect to such claim or litigation.

d.The indemnification provided for under this Agreement shall remain in full force and effect regardless of any investigation made by or on behalf of the indemnified party or any officer, director or controlling person of such indemnified party and shall survive the transfer of securities. The Company and each Holder of Registrable Securities participating in an offering also agrees to make such provisions as are reasonably requested by any indemnified party for contribution to such party in the event the Company’s or such Holder’s indemnification is unavailable for any reason.

e.If the indemnification provided under this Section 4.1 from the indemnifying party is unavailable or insufficient to hold harmless an indemnified party in respect of any losses, claims, damages, liabilities and expenses referred to herein, then the indemnifying party, in lieu of indemnifying the indemnified party, shall contribute to the amount paid or payable by the indemnified party as a result of such losses, claims, damages, liabilities and expenses in such proportion as is appropriate to reflect the relative fault of the indemnifying party and the indemnified party, as well as any other relevant equitable considerations. The relative fault of the indemnifying party and indemnified party shall be determined by reference to, among other things, whether any action in question, including any untrue or alleged untrue statement of a material fact or omission or alleged omission to state a material fact, was made by, or relates to information supplied by, such indemnifying party or indemnified party, and the indemnifying party’s and indemnified party’s relative intent, knowledge, access to information and opportunity to correct or prevent such action; provided, however, that the liability of any Holder under this Section 4.1(e) shall be limited to the amount of the net proceeds received by such Holder in such offering giving rise to such liability. The amount paid or payable by a party as a result of the losses or other liabilities referred to above shall be deemed to include, subject to the limitations set forth in Section 4.1(a), Section 4.1(b) and Section 4.1(c) above, any legal or other fees, charges or expenses reasonably incurred by such party in connection with any investigation or proceeding. The parties hereto agree that it would not be just and equitable if contribution pursuant to this Section 4.1(e) were determined by pro rata allocation or by any other method of allocation, which does not take account of the equitable considerations referred to in this Section 4.1(e). No person guilty of fraudulent misrepresentation (within the meaning of Section 11(f) of the Securities Act) shall be entitled to contribution pursuant to this Section 4.1(e) from any person who was not guilty of such fraudulent misrepresentation.

Section 5.1    Lock-Up. Each Holder agrees that it, he or she shall not Transfer any Registrable Securities until the expiration of the Lock-Up Period.

Section 5.2    Permitted Transferees. Notwithstanding the provisions set forth in Section 5.1, Transfers of the Registrable Securities that are held by the Holder or any of their Permitted Transferees (that have complied with this Section 5.2), are permitted to the following (each of which shall be considered a “Permitted Transferee”): (a) to the Company’s officers or directors, any affiliate or family member of any of the Company’s officers or directors, (b) in the case of an

entity, to such Holder’s Affiliates, members, stockholders, partners or other equity holders, (c) in the case of an individual, by gift to a member of such individual’s immediate family or to a trust, the beneficiary of which is a member of such individual’s immediate family, an affiliate of such individual or to a charitable organization; (d) in the case of an individual, by virtue of laws of descent and distribution upon death of such individual; (e) in the case of an individual, pursuant to a qualified domestic relations order; (f) by virtue of the laws of the State of Delaware; or (g) in the event of the Company’s liquidation, merger, capital stock exchange, reorganization or other similar transaction which results in all of the Company’s stockholders having the right to exchange their shares of Common Stock for cash, securities or other property subsequent to the Closing Date; provided, however, that in the case of clauses (a) through (f), these Permitted Transferees must enter into a written agreement with the Company agreeing to be bound by the transfer restrictions herein.

Section 6.1    Notices. All notices, demands, requests, instructions, claims, consents, waivers and other communications to be given or delivered under or by reason of the provisions of this Agreement shall be in writing and shall be deemed to have been given (a) when personally delivered (or, if delivery is refused, upon presentment), received by fax or email (with hard copy to follow) prior to 5:00 p.m. Eastern Time on a Business Day or delivery by reputable overnight express courier (charges prepaid) or (b) three (3) days following mailing by certified or registered mail, postage prepaid and return receipt requested. Unless another address is specified in writing, notices, demands and communications to a Holder or the Company shall be sent to the addresses indicated below:

Notices to any Holder:

At the address on file with the Company.

with a copy to (which shall not constitute notice):

Morrison Cohen LLP

909 Third Avenue, 27th Floor

New York, New York, 10022

Attention: David LaGalia, Esq.

Zachary Jacobs, Esq.

Fax: (212) 735-8708

Email: dlagalia@morrisoncohen.com

Eos Energy Storage LLC

3920 Park Ave

Edison, NJ 08820

Attention: Joe Mastrangelo

Email: jmastrangelo@eosenergystorage.com

with a copy to (which shall not constitute notice):

White & Case LLP

1221 Avenue of the Americas

New York, New York 10020-1095

Attention: Joel Rubinstein

Luke Laumann

Fax: (212) 354-8113

Email: joel.rubinstein@whitecase.com

a.This Agreement and the rights, duties and obligations of the Company hereunder may not be assigned or delegated by the Company in whole or in part.

b.Prior to the expiration of the Lock-up Period, no Holder may assign or delegate such Holder’s rights, duties or obligations under this Agreement, in whole or in part, except in connection with a Transfer of Registrable Securities by such Holder to a Permitted Transferee; provided, in each case, that such Permitted Transferee agrees to become bound by the transfer restrictions set forth in this Agreement. Following the expiration of the Lock-up Period, the rights granted to a Holder by the Company hereunder may be transferred or assigned (but only with all related obligations) by a Holder only to (i) a Permitted Transferee of such Holder, or (ii) a transferee or assignee that is a transferee or assignee of not less than 50,000 Registrable Securities (as presently constituted and subject to subsequent adjustments for share splits, share dividends, reverse share splits and the like); provided, that (x) such transfer or assignment of Registrable Securities is effected in accordance with applicable securities laws (subject to reasonable verification by the Company), (y) the Company is, within a reasonable time after such transfer, furnished with written notice of the name and address of such transferee and the Registrable Securities with respect to which such rights are being transferred and (z) such transferee agrees in a written instrument delivered to the Company to be bound by and subject to the terms and conditions of this Agreement.

c.This Agreement and the provisions hereof shall be binding upon and shall inure to the benefit of each of the parties and its successors and the permitted assigns of the Holders, which shall include Permitted Transferees.

d.This Agreement shall not confer any rights or benefits on any persons that are not parties hereto, other than as expressly set forth in this Agreement and this Section 6.2, except that the Founder Holders, severally and not jointly, shall be express third party beneficiaries of Section 2.2(b)(i) and Section 2.3(b).

e.No assignment by any party hereto of such party’s rights, duties and obligations hereunder shall be binding upon or obligate the Company unless and until the Company shall have received (i) written notice of such assignment as provided in Section 6.1 and (ii) the written agreement of the assignee, in the form attached hereto as Exhibit A, to be bound by the terms and provisions of this Agreement. Any transfer or assignment made other than as provided in this Section 6.2 shall be null and void.

f.A Unitholder (as defined in the Merger Agreement) may be admitted as a Holder herein after the execution of this Agreement upon the receipt by the Company of a duly completed and executed written agreement to be bound by the terms and provisions of this Agreement in form and substance satisfactory to the Company.

Section 6.3    Counterparts. This Agreement and agreements, certificates, instruments and documents entered into in connection herewith may be executed and delivered in one or more counterparts and by fax or email, each of which shall be deemed an original and all of which shall be considered one and the same agreement. No party hereto shall raise the use of a fax machine or email to deliver a signature or the fact that any signature or agreement or instrument was transmitted or communicated through the use of a fax machine or email as a defense to the formation or enforceability of a contract and each party hereto forever waives any such defense.

Section 6.4    Governing Law. This Agreement shall be governed by and construed and enforced in accordance with the laws of the State of New York, without regard to the principles of conflicts of laws thereof. Each party irrevocably submits to the exclusive jurisdiction of any New York State or United States Federal court sitting in The City of New York, Borough of Manhattan, over any suit, action or proceeding arising out of or relating to this Agreement. Each party irrevocably waives, to the fullest extent permitted by law, any objection that it may now or hereafter have to the laying of venue of any such suit, action or proceeding brought in such a court and any claim that any such suit, action or proceeding brought in such a court has been brought in an inconvenient forum. Any such process or summons to be served upon any party may be served by transmitting a copy thereof by registered or certified mail, return receipt requested, postage prepaid, addressed to it at the address set forth in Section 6.1. Such mailing shall be deemed personal service and shall be legal and binding upon any party in any action, proceeding or claim. Each party waives, to the fullest extent permitted by law, any other requirements of or objections to personal jurisdiction with respect thereto. Each party agrees that the other party shall be entitled to recover all of its reasonable attorneys’ fees and expenses relating to any action or proceeding and/or incurred in connection with the preparation therefor if any of them is the prevailing party in such action or proceeding. EACH PARTY HEREBY IRREVOCABLY WAIVES, TO THE FULLEST EXTENT PERMITTED BY APPLICABLE LAW, ANY AND ALL RIGHT TO TRIAL BY JURY IN ANY LEGAL PROCEEDING ARISING OUT OF OR RELATING TO THIS AGREEMENT OR THE TRANSACTIONS CONTEMPLATED HEREBY.

Section 6.5    Specific Performance. Each party hereto recognizes and affirms that in the event any of the provisions of this Agreement are not performed in accordance with their specific terms or otherwise are breached, money damages would be inadequate (and therefore the non-breaching party would have no adequate remedy at law) and the non-breaching party would be irreparably damaged. Accordingly, each party hereto agrees that each other party hereof shall be entitled to specific performance, an injunction or other equitable relief (without posting of bond or other security or needing to prove irreparable harm) to prevent breaches of the provisions of this Agreement and to enforce specifically this Agreement and the terms and provisions hereof in any proceeding, in addition to any other remedy to which such person may be entitled.

Section 6.6    Severability. Whenever possible, each provision of this Agreement shall be interpreted in such manner as to be effective and valid under applicable law, but if any provision of this Agreement or the application of any such provision to any person or circumstance shall be held to be prohibited by or invalid, illegal or unenforceable under applicable law in any respect

by a court of competent jurisdiction, such provision shall be ineffective only to the extent of such prohibition or invalidity, illegality or unenforceability, without invalidating the remainder of such provision or the remaining provisions of this Agreement. Furthermore, in lieu of such illegal, invalid or unenforceable provision, there shall be added automatically as a part of this Agreement a legal, valid and enforceable provision as similar in terms to such illegal, invalid, or unenforceable provision as may be possible.

Section 6.7    Interpretation. The headings and captions used in this Agreement have been inserted for convenience of reference only and do not modify, define or limit any of the terms or provisions hereof.

Section 6.8    Entire Agreement. This Agreement contains the entire agreement and understanding between the parties hereto with respect to the subject matter hereof and supersedes all prior agreements and understandings, whether written or oral, relating to such subject matter in any way.

Section 6.9    Amendments and Modifications. Upon the written consent of the Company and the Holders of at least a majority in interest of the Registrable Securities at the time in question, compliance with any of the provisions, covenants and conditions set forth in this Agreement may be waived, or any of such provisions, covenants or conditions may be amended or modified; provided, however, that notwithstanding the foregoing, any amendment hereto or waiver hereof that adversely affects one Holder, solely in its capacity as a holder of the shares of equity interests of the Company, in a manner that is materially different from the other Holders (in such capacity) shall require the consent of the Holder so affected. No course of dealing between any Holder or the Company and any other party hereto or any failure or delay on the part of a Holder or the Company in exercising any rights or remedies under this Agreement shall operate as a waiver of any rights or remedies of any Holder or the Company. No single or partial exercise of any rights or remedies under this Agreement by a party shall operate as a waiver or preclude the exercise of any other rights or remedies hereunder or thereunder by such party.

Section 6.10    Term. This Agreement shall terminate upon the date as of which no Holders (or permitted assignees under Section 6.2) hold any Registrable Securities. The provisions of Section 3.5 and Article IV shall survive any termination.

Section 6.11    Further Assurances. In connection with this Agreement and the transactions contemplated hereby, upon the written request by the Company, each Holder shall execute and deliver any additional documents and instruments and perform any additional acts that may be reasonably necessary to effectuate and perform the provisions of this Agreement and the transactions contemplated hereby.

a. Each Holder acknowledges that (i) the provisions of Article II of this Agreement require certain communications to be made by the Company or other Holders to such Holder that may result in such Holder acquiring MNPI (which may include, solely by way of illustration, the fact that an offering of the Company’s securities is pending or the number of Company securities or the identity of the selling Holders) (such communications, “RRA Communications”), and (ii) subject to the time limitations and the qualifications set forth herein, there is no limitation on the duration of time that such Holder may be in possession of MNPI included in such RRA

Communications and, except with respect to a notice provided pursuant to Article II, no requirement that the Company or other Holders make any public disclosure to cause information in such RRA Communications to cease to be MNPI; provided that the Company will notify each Holder if any proposed registration or offering for which an RRA Communications has been delivered pursuant to this Agreement has been terminated or aborted to the extent the knowledge of such registration or offering constitutes MNPI.

b.Each Holder agrees that it will maintain the confidentiality of MNPI in RRA Communications delivered to it and, to the extent such Holder is not a natural person, such confidential treatment shall be in accordance with procedures adopted by it in good faith to protect confidential information of third parties delivered to such Holder (“Policies”); provided that the obligation to maintain confidentiality of MNPI in RRA Communications shall cease when the information in the RRA Communications (i) is known or becomes known to the public in general (other than as a result of a breach of this Section by such Holder), or (ii) is or has been made known or disclosed to the Holder by a third party without a breach of any obligation of confidentiality such third party may have to the Company; provided further that a Holder may deliver or disclose MNPI in such RRA Communications to (1) to its affiliates, its and its affiliates’ respective directors, officers, employees, partners, members, agents, attorneys, consultants and financial and other advisors, and potential sources of capital (including potential limited partners) (collectively, the “Representatives”), but solely to the extent such disclosure reasonably relates to its evaluation of exercise of its rights under this Agreement and the sale of any Registrable Securities in connection with the subject of the notice, (2) to any federal, state, national, foreign or other regulatory or self-regulatory authority having jurisdiction over such Holder, or (3) to any Person if necessary to effect compliance with any law, rule, regulation, investigation, audit, request or order applicable to such Holder, including in response to any subpoena or other legal process, audit or examinations; provided further, that in the case of clause (1), the recipients of such MNPI in such RRA Communications are subject to the Policies or agree to hold confidential the MNPI in a manner substantially consistent with the terms of this Section 6 and that in the case of clauses (2) and (3), such Holder promptly notifies the Company of such disclosure to the extent such Holder is legally permitted to give such notice and it is reasonably practicable; provided, further, no such notice shall be required where disclosure is made (x) in response to a general request by a regulatory or self-regulatory authority or (y) in connection with a routine audit or examination by a bank examiner or auditor and such audit or examination does not reference the Company or this Agreement.

c.Each Holder, by its execution of this Agreement, hereby (i) acknowledges that it is aware that the U.S. securities laws prohibit any Person who has MNPI about a company from purchasing or selling, directly or indirectly, securities of such company (including entering into hedge transactions involving such securities), or from communicating such information to any other Person, and (ii) agrees that it will not use or permit any third party to use, and that it will use its commercially reasonable efforts to assure that none of its Representatives will use or permit any third party to use, any MNPI the Company provides in contravention of the U.S. securities laws and such Holder will cease trading in the Company’s securities while in possession of such MNPI.

d.Each Holder shall have the right, at any time and from time to time (including after receiving information regarding any potential Underwritten Offering), to elect not to receive RRA Communications that the Company or any other Holders otherwise are required to deliver pursuant to this Agreement by delivering to the Company a written statement signed by such Holder that it does not want to receive any RRA Communications (an “Opt-Out Request”); in which case and notwithstanding anything to the contrary in this Agreement the Company and other Holders shall not be required to, and shall not, deliver any RRA Communications for which the Holder has indicated in the Opt-Out Request that it does not want to receive hereunder to the extent that such RRA Communications would result in a Holder acquiring MNPI. An Opt-Out Request may state a date on which it expires or, if no such date is specified, shall remain in effect until the Holder notifies the Company that it withdraws the Opt-Out Request, and the Holder may, in its sole discretion, determine the scope and applicability of the Opt-Out Request as set forth in the Opt-Out Request. A Holder who previously has given the Company an Opt-Out Request may update or revoke such request at any time, and there shall be no limit on the ability of a Holder to issue, update and revoke subsequent Opt-Out Requests; provided that each Holder shall use commercially reasonable efforts to minimize the administrative burden on the Company arising in connection with any such Opt-Out Requests.

IN WITNESS WHEREOF, each of the undersigned has caused this Agreement to be executed as of the date first written above.

The undersigned is executing and delivering this Joinder pursuant to the Registration Rights Agreement, dated as of November 16, 2020 (as the same may hereafter be amended, the “Registration Rights Agreement”), among Eos Energy Enterprises, Inc., a Delaware corporation (the “Company”), and the other person named as parties therein.

By executing and delivering this Joinder to the Company, the undersigned hereby agrees to become a party to, to be bound by, and to comply with the provisions of the Registration Rights Agreement as a Holder in the same manner as if the undersigned were an original signatory to the Registration Rights Agreement, and the undersigned’s ________________ number of shares of _____________________ shall be included as Registrable Securities under the Registration Rights Agreement.

Accordingly, the undersigned has executed and delivered this Joinder as of the ___ day of ____________, ____.

[•]

        Signature of Stockholder

[Print Name of Stockholder]

Address:

Agreed and Accepted as of:

By: _____________________

    Its: