This statement is being jointly filed by the following persons (the “Reporting Persons”):

Discovery Equity Partners, L.P. (“Discovery Equity Partners”) is an Illinois limited partnership primarily engaged in the business of investing in securities.

Discovery Group I, LLC (“Discovery Group”) is a Delaware limited liability company and a registered investment adviser under the Investment Advisers Act of 1940, as amended, that is primarily engaged in the business of investing in securities on behalf of institutional clients.

The business address of each of the Reporting Persons is 300 South Wacker Drive, Suite 600, Chicago, Illinois 60606.

The Reporting Persons acquired beneficial ownership of the shares of Common Stock reported herein as part of their investment activities on behalf of Discovery Equity Partners.  The Reporting Persons acquired the shares of Common Stock reported herein because they believe that the trading prices of the Common Stock do not adequately reflect the potential value of the Company’s underlying business and assets.

The Reporting Persons intend to review and evaluate their investment in the Common Stock on an ongoing basis and may, depending upon their evaluation of the business and prospects of the Company, or such other considerations as they may deem relevant, determine to increase, decrease, or dispose of their holdings of Common Stock.  As a part of such review and evaluation, the Reporting Persons may hold discussions with the Company’s management and directors, other shareholders and other interested parties.

Except as otherwise described in this Item 4, the Reporting Persons do not have present plans or proposals that relate to or would result in any of the following (although the Reporting Persons reserve the right to develop such plans or proposals or any other plans relating to the Company and to take action with respect thereto):  (i) the acquisition by any person of additional securities of the Company, or the disposition of securities of the Company; (ii) an extraordinary corporate transaction, such as a merger, reorganization, or liquidation, involving the Company or any of its subsidiaries; (iii) a sale or transfer of a material amount of assets of the Company or any of its subsidiaries; (iv) any change in the present board of directors or management of the Company, including any plans or proposals to change the number or term of directors or to fill any existing vacancies on the board; (v) any material change in the present capitalization or dividend policy of the Company; (vi) any other material change in the Company’s business or corporate structure; (vii) changes in the Company’s certificate of incorporation, bylaws, or instruments corresponding thereto or other actions that may impede the acquisition of control of the Company by any person; (viii) causing a class of securities of the Company to be delisted from a national securities exchange or to cease to be authorized to be quoted in an inter-dealer quotation system of a registered national securities association; (ix) a class of equity securities of the Company becoming eligible for termination of registration pursuant to Section 12(g)(4) of the Securities Exchange Act of 1934, as amended; or (x) any action similar to any of those enumerated above.

The information concerning percentages of ownership set forth below is based on 76,743,217 shares of Common Stock outstanding as of August 7, 2017 in the Company’s Quarterly Report on Form 10-Q for the quarterly period ended July 1, 2017.

Discovery Equity Partners beneficially owns 4,376,434 shares of Common Stock as of August 24, 2017, which represents 5.7% of the outstanding Common Stock.

Discovery Group beneficially owns 4,376,434 shares of Common Stock as of August 24, 2017, which represents 5.7% of the outstanding Common Stock.

Discovery Group is the investment manager of Discovery Equity Partners.   Discovery Group exercises ultimate voting and dispositive power of the securities held by Discovery Equity Partners. As a consequence, Discovery Group may be deemed to share beneficial ownership of all of the shares of Common Stock owned by Discovery Equity Partners. Voting and disposition decisions at Discovery Group with respect to the investment of such securities are made by a five-person investment committee (the “Committee”) which makes such investment decisions by majority vote. No member of the Committee may act individually to vote or sell shares of Common Stock held by Discovery Equity Partners, nor does any such member have a veto right concerning the vote or sale of any such common stock. Accordingly, no individual member of the Committee is deemed to beneficially own, and each individual member of the Committee expressly disclaims beneficial ownership of, within the meaning of Rule 13d-3, any shares of Common Stock held by Discovery Equity Partners solely by virtue of the fact that he or she is a member of the Committee.

The transactions in Common Stock effected by the Reporting Persons during the past 60 days are set out in Exhibit 1 hereto.

No person other than Discovery Equity Partners is known to any Reporting Person to have the right to receive or the power to direct the receipt of dividends from, or the proceeds from the sale of, any of the shares of Common Stock reported herein.

Mark Buckley

Attorney-in-Fact for Michael R. Murphy