Exhibit 4.3

DESCRIPTION OF REGISTRANT’S SECURITIES REGISTERED PURSUANT TO SECTION 12 OF THE SECURITIES EXCHANGE ACT OF 1934

The following description of our capital stock is intended as a summary only and therefore is not a complete description of our capital stock. This description is based upon, and is qualified by reference to, our amended and restated certificate of incorporation (the “Amended Certificate”), our amended and restated bylaws (the “Amended Bylaws”) and applicable provisions of Delaware corporate law. You should read our Amended Certificate and Amended Bylaws, which are filed as exhibits to our Annual Report on Form 10-K, to which this exhibit is also appended.

Our authorized capital stock consists of 35,000,000 shares of common stock, par value $0.0001 per share, and 2,000,000 shares of preferred stock, par value $0.0001 per share.

Our common stock is the only class of securities registered under Section 12 of the Securities Exchange Act of 1934, as amended (the “Exchange Act”).

Common Stock

Holders of our common stock are entitled to one vote for each share held on all matters submitted to a vote of stockholders and do not have cumulative voting rights. An election of directors by our stockholders shall be determined by a plurality of the votes cast by the stockholders entitled to vote in the election. Subject to the supermajority votes for some matters, other matters shall be decided by the affirmative vote of our stockholders having a majority in voting power of the votes cast by the stockholders present or represented and voting on such matter. Holders of common stock are entitled to receive proportionately any dividends as may be declared by our board of directors, subject to any preferential dividend rights of any series of preferred stock that we may designate and issue in the future.

In the event of our liquidation or dissolution, the holders of common stock are entitled to receive on a pro rata basis our net assets available for distribution to stockholders after the payment of all debts and other liabilities, subject to the prior rights of any holders of outstanding preferred stock. Holders of common stock have no preemptive, subscription, redemption or conversion rights. Our outstanding shares of common stock are validly issued, fully paid and nonassessable. The rights, preferences and privileges of holders of common stock are subject to and may be adversely affected by the rights of the holders of shares of any series of preferred stock that we may designate and issue in the future.

Preferred Stock

Under the terms of our Amended Certificate our board of directors is authorized to direct us to issue shares of preferred stock in one or more series without stockholder approval. Our board of directors has the discretion to determine the rights, preferences, privileges and restrictions, including voting rights, dividend rights, conversion rights, redemption privileges and liquidation preferences, of each series of preferred stock.

The purpose of authorizing our board of directors to issue preferred stock and determine its rights and preferences is to eliminate delays associated with a stockholder vote on specific issuances. The issuance of preferred stock, while providing flexibility in connection with possible acquisitions, future financings and other corporate purposes, could have the effect of making it more difficult for a third party to acquire, or could discourage a third party from seeking to acquire, a majority of our outstanding voting stock.

Registration Rights

Under our registration rights agreement dated as of December 19, 2014, holders of 2,273,847 shares of common stock, or their transferees, have the right to require us to register their shares under the Securities Act of 1933, as amended (the “Securities Act”) so that those shares may be publicly resold, or to include their shares in any registration statement we file, in each case as further described below.

Demand Registration Rights

If holders of more than 50% of the registrable securities request us to file a registration statement under the Securities Act for a public offering of such shares of registrable securities having an aggregate offering price of at least $10,000,000, we must, within ten days after the receipt of such notice, notify all holders of registrable securities of such request and shall use its reasonably diligent efforts to register under the Securities Act the registrable securities of all holders who so request within 90 days after the date of our notice; provided, however, that we are obligated to register only shares of common stock pursuant to the agreement. We are obligated to effect a maximum of two such demand registrations.

Piggyback/Incidental Registration Rights

Whenever we propose to register any common stock for our own or others’ account under the Securities Act for a public offering for cash, other than a registration relating to employee benefit plans, we must give each holder of registrable securities prompt written notice of its intent to do so. Upon the written request of any such holder given within 10 days after receipt of such notice, we will cause to be included in such registration all of the registrable securities that such holder requests; provided, however, that we are obligated to register only shares of our common stock pursuant to the agreement. If we are advised in writing by any managing underwriter of the securities being offered pursuant to any registration statement that the number of shares to be sold by persons other than us is greater than the number of such shares that can be offered without adversely affecting the offering, we may reduce pro rata the number of shares of registrable securities offered for the accounts of such persons to a number deemed satisfactory by such managing underwriter; and a managing underwriter will have the right to exclude registrable securities entirely pursuant to the preceding clause.

Form S-3 Registration Rights

If, at a time when Form S-3 (or any successor thereto) is available for such registration, we receive from holders of more than 15% of the registrable securities a written request or requests that we effect a registration on Form S-3 of registrable securities having an aggregate offering price of at least $5,000,000 (based on the then current public market price), we will promptly give written notice of the proposed registration to all other holders of registrable securities and, as soon as reasonably practicable, effect such registration and all such related qualifications and compliances as may be requested and as would permit the sale and distribution of all registrable securities as are specified in such request and any written requests of other holders given within 10 days after receipt of such notice; provided, however, that the Company shall not be obligated to effect any such registration pursuant to the agreement: (i) if Form S-3 is not available for such offering by the applicable holders; or (ii) if we furnish to the applicable holders a certificate signed by the chief executive officer stating that in the good faith judgment of the board of directors, it would be seriously detrimental to us and our stockholders for such Form S-3 registration to be effected at such time, in which event we will have the right to defer the filing of the Form S-3 registration statement for a period of not more than 120 days after receipt of the request of the holder or holders; provided, however, that we may not utilize this right more than twice in any 12-month period. We are not obligated to file more than two registrations under this provision.

Other Provisions and Expenses

A registrable security will cease to be a registrable security when (i) a registration statement covering such registrable security has been declared effective by the SEC and it has been disposed of pursuant to such effective registration statement; or (ii) such registrable security could be sold pursuant to Rule 144 (or any successor or comparable provision) without any volume restriction.

Other than underwriting discounts and commissions and certain other expenses, we will be required to pay all expenses incurred by us related to any registration effected pursuant to the exercise of these registration rights. These expenses may include all registration and filing fees, printing expenses, fees and disbursements of our counsel, reasonable fees and disbursements of a counsel for the selling stockholders and blue sky fees and expenses.

Warrant to Purchase Common Stock

In connection with the initial public offering of our common stock (the “IPO”), we issued to ThinkEquity, a division of Fordham Financial Management, Inc. (the “Representative”), a warrant (the “Representative’s Warrants”) to purchase 100,000 shares of our common stock at an exercise price of $7.50 per share (125% of our IPO price per share). The exercise price and number of shares issuable upon exercise of the warrants may be adjusted in certain circumstances including in the event of a stock dividend or our recapitalization, reorganization, merger or consolidation. However, the warrant exercise price or underlying shares will not be adjusted for issuances of shares of common stock at a price below the warrant exercise price. The Warrant is exercisable at any time, from time to time, in whole or in part, during the four-year period commencing one year from the effective date of the registration statement related to this offering.

The Representative’s Warrants and the shares of common stock underlying the Representative’s Warrants have been deemed compensation by FINRA and are, therefore, subject to a 180-day lock-up pursuant to FINRA Rule 5110(g)(1). The Representative or permitted assignees under such rule may not sell, transfer, assign, pledge, or hypothecate the Representative’s Warrants or the securities underlying the Representative's Warrants, nor will the representative engage in any hedging, short sale, derivative, put, or call transaction that would result in the effective economic disposition of the Representative's Warrants or the underlying shares of common stock for a period of 180 days from January 28, 2020. Additionally, the Representative's Warrants may not be sold, transferred, assigned, pledged, or hypothecated for a 180-day period following January 28, 2020, except to any underwriter and selected dealer participating in the offering and their bona fide officers or partners. The Representative's Warrants provide for registration rights upon request, in certain cases. The demand registration right provided will not be greater than five years from the effective date of this registration statement in compliance with FINRA Rule 5110(f)(2)(G)(iv). The piggyback registration right provided will not be greater than seven years from the effective date of this registration statement in compliance with FINRA Rule 5110(f)(2)(G)(v). We will bear all fees and expenses attendant to registering the securities issuable on exercise of the Representative’s Warrants other than underwriting commissions incurred and payable by the holders.

Anti-Takeover Effects of Delaware Law and Our Amended Certificate and Amended Bylaws

Some provisions of Delaware law, our Amended Certificate and Amended Bylaws could make the following transactions more difficult: an acquisition of us by means of a tender offer; an acquisition of us by means of a proxy contest or otherwise; or the removal of our incumbent officers and directors. It is possible that these provisions could make it more difficult to accomplish or could deter transactions that stockholders may otherwise consider to be in their best interest or in our best interests, including transactions which provide for payment of a premium over the market price for our shares.

These provisions, summarized below, are intended to discourage coercive takeover practices and inadequate takeover bids. These provisions are also designed to encourage persons seeking to acquire control of us to first negotiate with our board of directors. We believe that the benefits of the increased protection of our potential ability to negotiate with the proponent of an unfriendly or unsolicited proposal to acquire or restructure us outweigh the disadvantages of discouraging these proposals because negotiation of these proposals could result in an improvement of their terms.

Authorized but Unissued Shares

Our authorized but unissued shares of common stock and preferred stock are available for future issuance without stockholder approval. These additional shares may be utilized for a variety of corporate purposes, including future public offerings to raise additional capital and corporate acquisitions. The existence of authorized but unissued shares of common stock and preferred stock could render more difficult or discourage an attempt to obtain control of a majority of our common stock by means of a proxy contest, tender offer, merger or otherwise.

Stockholder Meetings

Any action to be taken by our stockholders must be effected at a duly called annual or special meeting of stockholders and not be taken by written consent.

Requirements for Advance Notification of Stockholder Nominations and Proposals

Stockholders seeking to present proposals before a meeting of stockholders or to nominate candidates for election as directors at a meeting of stockholders must provide advance notice in writing, and also specify requirements as to the form and content of a stockholder's notice.

Delaware Anti-Takeover Statute

We are subject to Section 203 of the General Corporation Law of the State of Delaware, which prohibits persons deemed to be “interested stockholders” from engaging in a “business combination” with a publicly held Delaware corporation for three years following the date these persons become interested stockholders unless the business combination is, or the transaction in which the person became an interested stockholder was, approved in a prescribed manner or another prescribed exception applies. Generally, an “interested stockholder” is a person who, together with affiliates and associates, owns, or within three years prior to the determination of interested stockholder status did own, 15% or more of a corporation's voting stock. Generally, a “business combination” includes a merger, asset or stock sale, or other transaction resulting in a financial benefit to the interested stockholder. The existence of this provision may have an anti-takeover effect with respect to transactions not approved in advance by the board of directors.

Choice of Forum

The Court of Chancery of the State of Delaware is the exclusive forum in which we and our directors may be sued by our stockholders, to the fullest extent permitted by law, for:

Our Amended Bylaws do not apply to suits brought to enforce a duty or liability created by the Securities Act or the Exchange Act, or any other claim for which federal courts have exclusive jurisdiction.

These choice of forum provisions may limit a stockholder's ability to bring a claim in a judicial forum that it finds favorable for disputes with us or any of our directors, officers, or other employees, which may discourage lawsuits with respect to such claims. Alternatively, if a court were to find either choice of forum provision contained in our Amended Bylaws to be inapplicable or unenforceable in an action, we may incur additional costs associated with resolving such action in other jurisdictions, which could harm our business, results of operations, and financial condition.

Advance Notice Requirements

Our Amended Bylaws establish an advance notice procedure for stockholder proposals to be brought before an annual meeting of our stockholders, including proposed nominations of persons for election to the board of directors. Stockholders at an annual meeting will only be able to consider proposals or nominations specified in the notice of meeting or brought before the meeting by or at the direction of the board of directors or by a stockholder who was a stockholder of record on the record date for the meeting, who is entitled to vote at the meeting and who has given our Secretary timely written notice, in proper form, of the stockholder's intention to bring that business before the meeting. Although our Amended Bylaws do not give the board of directors the power to approve or disapprove stockholder nominations of candidates or proposals regarding other business to be conducted at a special or annual meeting, our Amended Bylaws may have the effect of precluding the conduct of certain business at a meeting if the proper procedures are not followed or may discourage or deter a potential acquirer from conducting a solicitation of proxies to elect its own slate of directors or otherwise attempting to obtain control of us.

Transfer Agent and Registrar

The transfer agent and registrar for our common stock is American Stock Transfer & Trust Company, LLC.

National Securities Exchange Listing

Our common stock listed on NYSE American under the symbol “ANVS.”