Description of Securities

Exhibit 4.7

DESCRIPTION OF REGISTRANT’S SECURITIES

REGISTERED PURSUANT TO SECTION 12 OF THE

SECURITIES EXCHANGE ACT OF 1934

The following description of the Company’s securities is based upon the Company’s amended and restated certificate of incorporation (“Charter”), the Company’s Bylaws (“Bylaws”) and applicable provisions of law. We have summarized certain portions of the Charter and Bylaws below. The summary is not complete and is subject to, and is qualified in its entirety by express reference to, the provisions of our Charter and Bylaws, each of which is filed as an exhibit to the Annual Report on Form 10-K of which this Exhibit 4.7 is a part.

Authorized Capital Stock

Pursuant to Charter, our authorized capital stock consists of 40,000,000 shares of common stock, $0.0001 par value, and 1,000,000 shares of undesignated preferred stock, $0.0001 par value.

Units

Each unit consists of one share of common stock, one right and one warrant. Each right entitles the holder to receive one-tenth of one share of common stock. Each warrant entitles the holder to purchase one share of common stock.

Common Stock

Authorization. The outstanding shares of the Company’s common stock are duly authorized, validly issued, fully paid and nonassessable.

Voting Rights. Common stockholders of record are entitled to one vote for each share held on all matters to be voted on by stockholders.

Preemptive Rights, Etc. Our stockholders have no preemptive or other subscription rights. There are no sinking fund provisions applicable to our common stock.

Preferred Stock

Our Charter provides that shares of preferred stock may be issued from time to time in one or more series. Our board of directors will be authorized to fix the voting rights, if any, designations, powers, preferences, the relative, participating, optional or other special rights and any qualifications, limitations and restrictions, applicable to the shares of each series. Our board of directors will be able, without stockholder approval, to issue preferred stock with voting and other rights that could adversely affect the voting power and other rights of the holders of the common stock and could have anti-takeover effects.

Rights

Exchangeability. Each holder of a right will receive one-tenth (1/10) of one share of common stock upon consummation of our initial business combination. No additional consideration will be required to be paid by a holder of rights in order to receive its additional shares upon consummation of an initial business combination.

If we enter into a definitive agreement for a business combination in which we will not be the surviving entity, the definitive agreement will provide for the holders of rights to receive the same per share consideration the holders of the common stock will receive in the transaction on an as-converted into common stock basis, and each holder of a right will be required to affirmatively convert its rights in order to receive the 1/10 share underlying each right (without paying any additional consideration) upon consummation of the business combination. More specifically, the right holder will be required to indicate its election to convert the rights into underlying shares as well as to return the original rights certificates to us.

Fractional Shares. We will not issue fractional shares upon exchange of the rights. If, upon exchange of the rights, a holder would be entitled to receive a fractional interest in a share, we will, upon exchange, either round up to the nearest whole number the number of shares to be issued to the right holder or otherwise comply with Section 155 of the Delaware General Corporation Law (which provides that Delaware companies shall either (1) arrange for the disposition of fractional interests by those entitled thereto, (2) pay in cash the fair value of fractions of a share as of the time when those entitled to receive such fractions are determined or (3) issue scrip or warrants in registered form (either represented by a certificate or uncertificated) or in bearer form (represented by a certificate) which shall entitle the holder to receive a full share upon the surrender of such scrip or warrants aggregating a full share). We will make the determination of how we are treating fractional shares at the time of our initial business combination and will include such determination in the proxy materials we will send to stockholders for their consideration of such initial business combination.

Warrants

Exercisability. Each warrant is exercisable to purchase one share of our common stock. No fractional shares will be issued upon exercise of the warrants.

Exercise Price. $11.50 per share, subject to adjustment.

Exercise Period. The warrants will become exercisable 30 days after the consummation of our initial business combination. The warrants will expire five years after the consummation of our initial business combination, at 5:00 p.m., New York time, or earlier upon redemption or our liquidation.

No warrants will be exercisable for cash unless we have an effective and current registration statement covering the shares of common stock issuable upon exercise of the warrants and a current prospectus relating to such shares of common stock is available, and such shares are registered, qualified or exempt from registration under the securities laws of the state of residence of the holder. Notwithstanding the foregoing, if a registration statement covering the shares of common stock issuable upon exercise of the public warrants has not been declared effective by the end of 60 business days following the closing of our initial business combination, warrant holders may, until such time as there is an effective registration statement and during any period when we shall have failed to maintain an effective registration statement, exercise warrants on a cashless basis pursuant to the exemption provided by Section 3(a)(9) of the Securities Act.

We have agreed to use our best efforts to file and have an effective registration statement covering the shares of common stock issuable upon exercise of the warrants, to maintain a current prospectus relating to those shares of common stock until the earlier of the date the warrants expire or are redeemed and the date on which all of the warrants have been exercised, and to qualify the resale of such shares under state blue sky laws, to the extent an exemption is not available.

Redemption of Warrants. Once the warrants become exercisable, we may redeem the outstanding warrants in whole and not in part, at a price of $0.01 per warrant, upon not less than 30 days’ prior written notice of redemption (the “30-day redemption period”) to each warrant holder, and if, and only if, the reported last sale price of the common stock (or the closing bid price of our common stock in the event shares of our common stock are not traded on any specific day) equals or exceeds $18.00 per share for any 20 trading days within a 30 trading day period ending three business days before we send the notice of redemption to the warrant holders. We will not redeem the warrants unless an effective registration statement covering the shares of common stock issuable upon exercise of the warrants is current and available throughout the 30-day redemption period.

If we call the warrants for redemption as described above, we will have the option to require all holders that wish to exercise warrants to do so on a “cashless basis.” In such event, each holder would pay the exercise price by surrendering the warrants for that number of shares of common stock equal to the quotient obtained by dividing (x) the product of the number of shares of common stock underlying the warrants, multiplied by the difference between the exercise price of the warrants and the “fair market value” (defined below) by (y) the fair market value. In this case, the “fair market value” shall mean the average reported last sale price of the shares of common stock for the 10 trading days ending on the third trading day prior to the date on which the notice of redemption is sent to the holders of warrants. Whether we will exercise our option to require all holders to exercise their warrants on a “cashless basis” will depend on a variety of factors including the price of our shares of common stock at the time the warrants are called for redemption, our cash needs at such time and concerns regarding dilutive stock issuances.

Fractional Shares. If, upon exercise of the warrants, a holder would be entitled to receive a fractional interest in a share, we will comply with Section 155 of the Delaware General Corporation Law (which provides that Delaware companies shall either (1) arrange for the disposition of fractional interests by those entitled thereto, (2) pay in cash the fair value of fractions of a share as of the time when those entitled to receive such fractions are determined or (3) issue scrip or warrants in registered form (either represented by a certificate or uncertificated) or in bearer form (represented by a certificate) which shall entitle the holder to receive a full share upon the surrender of such scrip or warrants aggregating a full share).

Certain Provisions of the Company’s Charter and Bylaws

Stockholder Proposals and Director Nominations. To be properly brought before an annual meeting of stockholders, any stockholder proposal or stockholder nomination for the board of directors must be delivered to the Company’s secretary between 60 and 90 days before the annual meeting date. Such notice must contain information specified in the Bylaws as to the director nominee or proposal of other business, information about the stockholder making the nomination or proposal and the beneficial owner, if any, on behalf of whom the nomination or proposal is made, including name and address, class and number of shares owned, and representations regarding the intention to make such a proposal or nomination and to solicit proxies in support of it. With respect to director nominees, we may require any proposed nominee to furnish information concerning his or her eligibility to serve as an independent director or that could be material to a reasonable stockholder’s understanding of the independence of the nominee and to provide a statement as to whether such nominee, if elected, intends to comply with the Company’s policies and procedures as applicable to the board of directors.

Exclusive Forum Selection. Our Charter requires, to the fullest extent permitted by law, that derivative actions brought in our name, actions against directors, officers and employees for breach of fiduciary duty and other similar actions may be brought only in the Court of Chancery in the State of Delaware and, if brought outside of Delaware, the stockholder bringing the suit will be deemed to have consented to service of process on such stockholder’s counsel; provided that Allegro’s stockholders will not be deemed to have waived Allegro’s compliance with federal securities laws and the rules and regulations thereunder and can therefore bring claims for breach of these provisions in any appropriate forum. Any person or entity purchasing or otherwise acquiring any interest in shares of Allegro’s capital stock shall be deemed to have notice of and consented to the forum provisions in the Charter.

Certain Anti-Takeover Provisions of Delaware Law

We will be subject to the provisions of Section 203 of the Delaware General Corporation Law regulating corporate takeovers upon completion of this offering. This statute prevents certain Delaware corporations, under certain circumstances, from engaging in a “business combination” with:

A “business combination” includes a merger or sale of more than 10% of our assets. However, the above provisions of Section 203 do not apply if:

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