Description of capital stock

The following is a description of the material terms of, and is qualified in its entirety by, our amended and restated certificate of incorporation and amended and restated bylaws.

Our purpose is to engage in any lawful act or activity for which corporations may now or hereafter be organized under the DGCL. Our authorized capital stock consists of 750,000,000 shares of common stock, par value $0.01 per share, and 75,000,000 shares of preferred stock, par value $0.01 per share (including 25,000,000 shares of Mandatory Convertible Preferred Stock).

As of December 31, 2019, there were (i) 572,837,180 shares of common stock outstanding, of which 282,053,962 shares were held by 87 holders of record (which stockholder figure does not include a substantially greater number of holders whose shares are held of record by banks, brokers, and other financial institutions) and (ii) 20,700,000 shares of Mandatory Convertible Preferred Stock outstanding. As of December 31, 2019, there were 27,831,456 shares of common stock subject to outstanding options, restricted shares, restricted stock units and performance stock units.

Unless our Board of Directors determines otherwise, we will issue all shares of our capital stock in uncertificated form.

Holders of our common stock are entitled to one vote for each share held of record on all matters on which stockholders are entitled to vote generally, including the election or removal of directors, subject to certain limitations. The holders of our common stock do not have cumulative voting rights in the election of directors. Upon our liquidation, dissolution or winding up or the sale of all or substantially all of our assets and after payment in full of all amounts required to be paid to creditors and to the holders of preferred stock having liquidation preferences, if any, the holders of our common stock will be entitled to receive our remaining assets available for distribution on a pro rata basis. Holders of our common stock do not have preemptive, subscription, redemption or conversion rights. The common stock is not subject to further calls or assessment by us. There are no redemption or sinking fund provisions applicable to the common stock. All shares of our common stock that are outstanding are fully paid and non-assessable. The rights, powers, preferences and privileges of holders of our common stock will be subject to those of the holders of any shares of our preferred stock we may authorize and issue in the future.

Our amended and restated certificate of incorporation authorizes our Board of Directors to establish one or more series of preferred stock (including convertible preferred stock). Unless required by law or by the rules of the NYSE, the authorized shares of preferred stock will be available for issuance without further stockholder action. Our Board of Directors is able to

determine, with respect to any series of preferred stock, the terms and rights of that series, including:

We could issue a series of preferred stock that could, depending on the terms of the series, impede or discourage an acquisition attempt or other transaction that some, or a majority, of you might believe to be in your best interests or in which you might receive a premium for your common stock over the market price of the common stock. Additionally, the issuance of preferred stock may adversely affect the holders of our common stock by restricting dividends on the common stock, diluting the voting power of the common stock or subordinating the liquidation rights of the common stock. As a result of these or other factors, the issuance of preferred stock could have an adverse impact on the market price of our common stock.

Unless converted earlier as described below, each share of the Mandatory Convertible Preferred Stock will automatically convert, subject to anti-dilution adjustments described in the certificate of designations setting forth the terms of the Mandatory Convertible Preferred Stock (the

“Certificate of Designations”), on the mandatory conversion date, which is expected to be May 15, 2022, into a number of shares of our common stock equal to the conversion rate described below.

The “Conversion Rate,” which is the number of shares of our common stock issuable upon conversion of each share of the Mandatory Convertible Preferred Stock on the mandatory conversion date (excluding any shares of our common stock issued in respect of accrued and unpaid dividends, as described below), will be as follows:

“Settlement Period” means the 20 consecutive Trading Day (as defined in the Certificate of Designations) period beginning on, and including, the 21st Scheduled Trading Day (as defined in the Certificate of Designations) immediately preceding May 15, 2022.

“VWAP” per share of our common stock on any Trading Day means the per share volume-weighted average price as displayed on Bloomberg page “AVTR <EQUITY> AQR” (or its equivalent successor if such page is not available) in respect of the period from the scheduled open of trading until the scheduled close of trading of the primary trading session on such Trading Day (or, if such volume weighted average price is not available, the market value per share of our common stock on such Trading Day as determined, using a volume-weighted average method, by a nationally recognized independent investment banking firm retained by us for this purpose). The “Average VWAP” per share over a certain period means the arithmetic average of the VWAP per share for each Trading Day in the relevant period.

At any time prior to May 15, 2022, holders may elect to convert each share of the Mandatory Convertible Preferred Stock into shares of our common stock at the Minimum Conversion Rate. If holders elect to convert any shares of the Mandatory Convertible Preferred Stock during a specified period beginning on the effective date of a fundamental change (as defined in the

Certificate of Designations), such shares of the Mandatory Convertible Preferred Stock will be converted into shares of our common stock at a Conversion Rate including a make-whole amount based on the present value of future dividend payments.

Dividends on the Mandatory Convertible Preferred Stock are payable on a cumulative basis when, as and if declared by our Board of Directors, or an authorized committee thereof, at an annual rate of 6.250% on the liquidation preference of $50.00 per share of Mandatory Convertible Preferred Stock. We may pay any declared dividend on the shares of Mandatory Convertible Preferred Stock (whether for a current dividend period or any prior dividend period, including in connection with the payment of declared and unpaid dividends), determined in our sole discretion (i) in cash; (ii) subject to certain limitations, by delivery of shares of our common stock; or (iii) through any combination of cash and shares of our common stock. Dividend payments on the Mandatory Convertible Preferred Stock are made on February 15, May 15, August 15 and November 15 of each year, commencing on August 15, 2019. If we elect to make any such payment of a declared dividend, or any portion thereof, in shares of our common stock, such shares will be valued for such purpose at 97% of the average volume weighted average price per share of our common stock over the five consecutive Trading Day period beginning on, and including, the seventh Scheduled Trading Day prior to the applicable dividend payment date, subject to certain limitations described in the Certificate of Designations.

Except as specifically required by Delaware law or our amended and restated certificate of incorporation, and except as described below, the holders of Mandatory Convertible Preferred Stock will have no voting rights or powers.

Whenever dividends on any shares of the Mandatory Convertible Preferred Stock have not been declared and paid for the equivalent of six or more dividend periods, whether or not for consecutive dividend periods (a “Nonpayment”), the authorized number of directors on our Board of Directors will, at the next annual meeting of stockholders or at a special meeting of stockholders as provided below, automatically be increased by two and the holders of such shares of the Mandatory Convertible Preferred Stock, voting together as a single class with holders of any and all other series of voting preferred stock (as defined in the Certificate of Designations) then outstanding, will be entitled, at our next annual meeting of stockholders or at a special meeting of stockholders, if any, as provided below, to vote for the election of a total of two additional members of our Board of Directors (the “Preferred Stock Directors”); provided, however, that the election of any such Preferred Stock Directors will not cause us to violate the corporate governance requirements of the NYSE (or any other exchange or automated quotation system on which our securities may be listed or quoted) that requires listed or quoted companies to have a majority of independent directors; and provided, further, that our Board of Directors shall, at no time, include more than two Preferred Stock Directors.

In the event of a Nonpayment, the holders of record of at least 25% of the shares of the Mandatory Convertible Preferred Stock and any other series of voting preferred stock may request that a special meeting of stockholders be called to elect such Preferred Stock Directors (provided, however, that if our next annual or a special meeting of stockholders is scheduled to be held within 90 days of the receipt of such request, the election of such Preferred Stock

Directors, to the extent otherwise permitted by our amended and restated bylaws, will, instead, be included in the agenda for and will be held at such scheduled annual or special meeting of stockholders). The Preferred Stock Directors will stand for reelection annually, and at each subsequent annual meeting of the stockholders, so long as the holders of the Mandatory Convertible Preferred Stock continue to have such voting powers.

If and when all accumulated and unpaid dividends on the Mandatory Convertible Preferred Stock have been paid in full, or declared and a sum or number of shares of our common stock sufficient for such payment shall have been set aside for the benefit of the holders thereof on the applicable Regular Record Date (as defined in the Certificate of Designations) (a “Nonpayment Remedy”), the holders of the Mandatory Convertible Preferred Stock shall immediately and, without any further action by us, be divested of the foregoing voting powers, subject to the revesting of such powers in the event of each subsequent Nonpayment. If such voting powers for the holders of the Mandatory Convertible Preferred Stock and all other holders of voting preferred stock have terminated, each Preferred Stock Director then in office shall automatically be disqualified as a director and shall no longer be a director and the term of office of each such Preferred Stock Director so elected will terminate at such time and the authorized number of directors on our Board of Directors shall automatically decrease by two.

Any Preferred Stock Director may be removed at any time, with or without cause, by the holders of record of a majority in voting power of the outstanding shares of the Mandatory Convertible Preferred Stock and any other series of voting preferred stock then outstanding (voting together as a single class) when they have the voting powers described above. In the event that a Nonpayment shall have occurred and there shall not have been a Nonpayment Remedy, any vacancy in the office of a Preferred Stock Director (other than prior to the initial election of Preferred Stock Directors after a Nonpayment) may be filled by the written consent of the Preferred Stock Director remaining in office, except in the event that such vacancy is created as a result of such Preferred Stock Director being removed, or if no Preferred Stock Director remains in office, by a vote of the holders of record of a majority in voting power of the outstanding shares of the Mandatory Convertible Preferred Stock and any other series of voting preferred stock then outstanding (voting together as a single class) when they have the voting powers described above; provided, however, that the election of any such Preferred Stock Directors will not cause us to violate the corporate governance requirements of the NYSE (or any other exchange or automated quotation system on which our securities may be listed or quoted) that requires listed or quoted companies to have a majority of independent directors. The Preferred Stock Directors will each be entitled to one vote per director on any matter that comes before our Board of Directors for a vote.

The Mandatory Convertible Preferred Stock have certain other voting powers with respect to certain amendments to our amended and restated certificate of incorporation or the Certificate of Designations establishing the terms of the Mandatory Convertible Preferred Stock or certain other transactions as described in such Certificate of Designations.

The DGCL permits a corporation to declare and pay dividends out of “surplus” or, if there is no “surplus,” out of its net profits for the fiscal year in which the dividend is declared and/or the preceding year. “Surplus” is defined as the excess of the net assets of the corporation over the amount determined to be the capital of the corporation by the Board of Directors. The capital of the corporation is typically calculated to be (and cannot be less than) the aggregate par value of all issued shares of capital stock. Net assets equal the fair value of the total assets minus total liabilities. The DGCL also provides that dividends may not be paid out of net profits if, after the payment of the dividend, capital is less than the capital represented by the outstanding stock of all classes having a preference upon the distribution of assets.

Declaration and payment of any dividend will be subject to the discretion of our Board of Directors. The time and amount of dividends will be dependent upon our financial condition, operations, cash requirements and availability, debt repayment obligations, capital expenditure needs and restrictions in our debt instruments, industry trends, the provisions of Delaware law affecting the payment of dividends to stockholders and any other factors our Board of Directors may consider relevant.

Our amended and restated certificate of incorporation, amended and restated bylaws and the DGCL, which are summarized in the following paragraphs, contain provisions that are intended to enhance the likelihood of continuity and stability in the composition of our Board of Directors. These provisions are intended to avoid costly takeover battles, reduce our vulnerability to a hostile change of control and enhance the ability of our Board of Directors to maximize stockholder value in connection with any unsolicited offer to acquire us. However, these provisions may have an anti-takeover effect and may delay, deter or prevent a merger or acquisition of our company by means of a tender offer, a proxy contest or other takeover attempt that a stockholder might consider is in its best interest, including those attempts that might result in a premium over the prevailing market price for the shares of common stock held by stockholders.

Delaware law does not require stockholder approval for any issuance of authorized shares. However, the listing requirements of the NYSE, which would apply if and so long as our common stock remains listed on the NYSE, require stockholder approval of certain issuances equal to or exceeding 20% of the then outstanding voting power or then outstanding number of shares of common stock. These additional shares may be used for a variety of corporate purposes, including future public offerings, to raise additional capital or to facilitate acquisitions.

Our Board of Directors may issue shares of preferred stock on terms calculated to discourage, delay or prevent a change of control of our company or the removal of our management. Moreover, our authorized but unissued shares of preferred stock will be available for future

issuances without stockholder approval and could be utilized for a variety of corporate purposes, including future offerings to raise additional capital, acquisitions and employee benefit plans.

One of the effects of the existence of unissued and unreserved common stock or preferred stock may be to enable our Board of Directors to issue shares to persons friendly to current management, which issuance could render more difficult or discourage an attempt to obtain control of our company by means of a merger, tender offer, proxy contest or otherwise, and thereby protect the continuity of our management and possibly deprive our stockholders of opportunities to sell their shares of common stock at prices higher than prevailing market prices.

Our amended and restated certificate of incorporation provides that our Board of Directors is initially divided into three classes of directors, with the classes to be as nearly equal in number as possible, and with each class consisting of one-third of the total number of directors. At the first and second annual meetings of stockholders following the date of the IPO, successors to the class of directors whose term expires at such annual meeting will be elected for a term expiring at the third annual meeting of stockholders following the date of the IPO. From and after the third annual meeting of stockholders following the date of the IPO, there will only be one class of directors, with each director serving one-year terms expiring at the next annual meeting of stockholders. Following the IPO, the classification of directors will have the effect of making it more difficult for stockholders to change the composition of our Board of Directors. Our amended and restated certificate of incorporation and amended and restated bylaws provide that, subject to any rights of holders of preferred stock to elect additional directors under specified circumstances, the number of directors will be fixed from time to time exclusively pursuant to a resolution adopted by the Board of Directors.

However, such restrictions will not apply if a stockholder becomes an interested stockholder inadvertently and (i) as soon as practicable divests itself of ownership of sufficient shares so that the stockholder ceases to be an interested stockholder and (ii) would not, at any time within the three-year period immediately prior to a business combination between the Company and such stockholder, have been an interested stockholder but for the inadvertent acquisition of ownership.

Generally, a “business combination” includes a merger, asset or stock sale or other transaction resulting in a financial benefit to the interested stockholder. Subject to certain exceptions, an “interested stockholder” is a person who, together with that person’s affiliates and associates, owns, or within the previous three years owned, 15% or more of our voting stock. For purposes of this section only, “voting stock” has the meaning given to it in Section 203 of the DGCL.

Under certain circumstances, this provision will make it more difficult for a person who would be an “interested stockholder” to effect various business combinations with a corporation for a three-year period. This provision may encourage companies interested in acquiring our company to negotiate in advance with our Board of Directors because the stockholder approval requirement would be avoided if our Board of Directors approves either the business combination or the transaction which results in the stockholder becoming an interested stockholder. These provisions also may have the effect of preventing changes in our Board of Directors and may make it more difficult to accomplish transactions which stockholders may otherwise deem to be in their best interests.

Our amended and restated certificate of incorporation provides that New Mountain Capital and its affiliates and any of its direct or indirect transferees and any group as to which such persons are a party do not constitute “interested stockholders” for purposes of this provision.

Our amended and restated certificate of incorporation and amended and restated bylaws provide that directors may be removed either with or without cause upon the affirmative vote of at least 66²/₃% in voting power of all outstanding shares of stock entitled to vote generally in the election of directors, voting together as a single class. In addition, our amended and restated certificate of incorporation and our amended and restated bylaws also provide that, subject to the rights granted to one or more series of preferred stock then outstanding or the rights granted to certain of our existing shareholders pursuant to contractual agreements in effect on or prior to our IPO, any vacancies on our Board of Directors will be filled only by the affirmative vote of a majority of the remaining directors, even if less than a quorum, or by a sole remaining director.

Under Delaware law, the right to vote cumulatively does not exist unless the certificate of incorporation specifically authorizes cumulative voting. Our amended and restated certificate of incorporation does not authorize cumulative voting. Therefore, stockholders holding a majority in voting power of the shares of our stock entitled to vote generally in the election of directors are able to elect all our directors.

Our amended and restated certificate of incorporation provides that special meetings of our stockholders may be called at any time only by or at the direction of the Board of Directors or the chairman of the Board of Directors. These provisions may have the effect of deferring, delaying or discouraging hostile takeovers, or changes in control or management of our company.

Our amended and restated bylaws establish advance notice procedures with respect to stockholder proposals and the nomination of candidates for election as directors, other than nominations made by or at the direction of the Board of Directors or a committee of the Board of Directors. In order for any matter to be “properly brought” before a meeting, a stockholder will have to comply with advance notice requirements and provide us with certain information. Generally, to be timely, a stockholder’s notice must be received at our principal executive offices not less than 90 days nor more than 120 days prior to the first anniversary date of the immediately preceding annual meeting of stockholders. Our amended and restated bylaws will also specify requirements as to the form and content of a stockholder’s notice.

Our amended and restated bylaws allow the chairman of the meeting at a meeting of the stockholders to adopt rules and regulations for the conduct of meetings which may have the effect of precluding the conduct of certain business at a meeting if the rules and regulations are not followed. These provisions may defer, delay or discourage a potential acquirer from conducting a solicitation of proxies to elect the acquirer’s own slate of directors or otherwise attempting to influence or obtain control of our company.

Pursuant to Section 228 of the DGCL, any action required to be taken at any annual or special meeting of the stockholders may be taken without a meeting, without prior notice and without a vote if a consent or consents in writing, setting forth the action so taken, is signed by the holders of outstanding stock having not less than the minimum number of votes that would be necessary to authorize or take such action at a meeting at which all shares of our stock entitled to vote thereon were present and voted, unless our amended and restated certificate of incorporation provides otherwise.

The DGCL provides generally that the affirmative vote of a majority of the outstanding shares entitled to vote thereon, voting together as a single class, is required to amend a corporation’s certificate of incorporation, unless the certificate of incorporation requires a greater percentage.

The following provisions in our amended and restated certificate of incorporation may be amended, altered, repealed or rescinded only by the affirmative vote of the holders of at least 66²/₃% in the voting power of all

outstanding shares of stock entitled to vote generally in the election of directors, voting together as a single class:

The combination of the initial classification of our Board of Directors, the lack of cumulative voting and the supermajority voting requirements will make it more difficult for our existing stockholders to replace our Board of Directors as well as for another party to obtain control of us by replacing our Board of Directors. Because our Board of Directors has the power to retain and discharge our officers, these provisions could also make it more difficult for existing stockholders or another party to effect a change in management.

These provisions may have the effect of deterring hostile takeovers, delaying, or preventing changes in control of our management or our company, such as a merger, reorganization or

tender offer. These provisions are intended to enhance the likelihood of continued stability in the composition of our Board of Directors and its policies and to discourage certain types of transactions that may involve an actual or threatened acquisition of us. These provisions are designed to reduce our vulnerability to an unsolicited acquisition proposal. The provisions are also intended to discourage certain tactics that may be used in proxy fights. However, such provisions could have the effect of discouraging others from making tender offers for our shares and, as a consequence, they also may inhibit fluctuations in the market price of our shares that could result from actual or rumored takeover attempts. Such provisions may also have the effect of preventing changes in management.

Under the DGCL, with certain exceptions, our stockholders will have appraisal rights in connection with a merger or consolidation of us. Pursuant to the DGCL, stockholders who properly request and perfect appraisal rights in connection with such merger or consolidation will have the right to receive payment of the fair value of their shares as determined by the Delaware Court of Chancery.

Under the DGCL, any of our stockholders may bring an action in our name to procure a judgment in our favor, also known as a derivative action, provided that the stockholder bringing the action is a holder of our shares at the time of the transaction to which the action relates or such stockholder’s stock thereafter devolved by operation of law.

Our amended and restated certificate of incorporation provides that unless we consent to the selection of an alternative forum, the state or federal courts (as appropriate) located within the State of Delaware shall, to the fullest extent permitted by law, be the sole and exclusive forum for any (i) derivative action or proceeding brought on behalf of our company, (ii) action asserting a claim of breach of a fiduciary duty owed by any director, officer, or other employee or stockholder of our company to us or our stockholders, creditors or other constituents, (iii) action against us or any of our directors or officers involving a claim or defense arising pursuant to any provision of the DGCL or our amended and restated certificate of incorporation or our amended and restated bylaws, (iv) action against us or any director or officer of the Company involving a claim or defense implicating the internal affairs doctrine, or (v) action against us or any of our directors or officers involving a claim or defense arising pursuant to the Exchange Act or the Securities Act. It is possible that these exclusive forum provisions may be challenged in court and may be deemed unenforceable in whole or in part. Our exclusive forum provision shall not relieve the company of its duties to comply with the federal securities laws and the rules and regulations thereunder, and our stockholders will not be deemed to have waived our compliance with these laws, rules and regulations.

Delaware law permits corporations to adopt provisions renouncing any interest or expectancy in certain opportunities that are presented to the corporation or its officers, directors or stockholders.

The DGCL authorizes corporations to limit or eliminate the personal liability of directors to corporations and their stockholders for monetary damages for breaches of directors’ fiduciary duties, subject to certain exceptions. Our amended and restated certificate of incorporation will include a provision that eliminates the personal liability of directors for monetary damages for any breach of fiduciary duty as a director, except to the extent such exemption from liability or limitation thereof is not permitted under the DGCL. The effect of these provisions is to eliminate the rights of us and our stockholders, through stockholders’ derivative suits on our behalf, to recover monetary damages from a director for breach of fiduciary duty as a director, including breaches resulting from grossly negligent behavior. However, exculpation does not apply to any director if the director has acted in bad faith, knowingly or intentionally violated the law, authorized illegal dividends or redemptions or derived an improper benefit from his or her actions as a director.

Our amended and restated bylaws provide that we must generally indemnify, and advance expenses to, our directors and officers to the fullest extent authorized by the DGCL. We also are expressly authorized to carry directors’ and officers’ liability insurance providing indemnification for our directors, officers and certain employees for some liabilities. We also have entered into indemnification agreements with our directors, which agreements require us to indemnify these individuals to the fullest extent permitted under Delaware law against liabilities that may arise by reason of their service to us, and to advance expenses incurred as a result of any proceeding against them as to which they could be indemnified. We believe that these indemnification and advancement provisions and insurance are useful to attract and retain qualified directors and executive officers.

The limitation of liability, indemnification and advancement provisions in our amended and restated certificate of incorporation and amended and restated bylaws may discourage stockholders from bringing a lawsuit against directors for breach of their fiduciary duty. These provisions also may have the effect of reducing the likelihood of derivative litigation against directors and officers, even though such an action, if successful, might otherwise benefit us and our stockholders. In addition, your investment may be adversely affected to the extent we pay the costs of settlement and damage awards against directors and officers pursuant to these indemnification provisions.

There is currently no pending material litigation or proceeding involving any of our directors, officers or employees for which indemnification is sought.