Description of Securities Registered Pursuant to Section 12 of the Securities Exchange Act of 1934

        Our Certificate of Incorporation and Bylaws contain certain provisions that are intended to enhance the likelihood of continuity and stability in the composition of the board of directors and which may have the effect of delaying, deterring or preventing a future takeover or change in control of the company unless such takeover or change in control is approved by the board of directors.

        These provisions include:

Our Certificate of Incorporation provides that our board of directors is divided into three classes of directors, with the classes as nearly equal in number as practicable possible. As a result, approximately one-third of our board of directors is elected each year. The classification of directors has the effect of making it more difficult for securityholders to change the composition of our board. Our Certificate of Incorporation also provides that, subject to any rights of holders of preferred stock to elect additional directors under specified circumstances, the number of directors will be fixed exclusively pursuant to a resolution adopted by our board of directors.

Our Certificate of Incorporation provides that securityholder action can be taken only at an annual or special meeting of securityholders and cannot be taken by written consent in lieu of a meeting. Our Certificate of Incorporation also provides that, except as otherwise required by law, special meetings of the securityholders can only be called pursuant to a resolution adopted by a majority of the board of directors. Except as described above, securityholders will not be permitted to call a special meeting or to require the board of directors to call a special meeting.

Our Certificate of Incorporation provides that our directors may be removed only for cause by the affirmative vote of at least 75% of the voting power of our outstanding shares of capital stock, voting together as a single class. This requirement of a supermajority vote to remove directors could enable a minority of our securityholders to prevent a change in the composition of our board.

Our Bylaws establish an advance notice procedure for securityholder proposals to be brought before an annual meeting of our securityholders, including proposed nominations of persons for election to the board of directors. Securityholders at an annual meeting may only 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 securityholder who was a securityholder 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 securityholder's intention to bring that business before the meeting. Although the Bylaws do not give the board of directors the power to approve or disapprove securityholder nominations of candidates or proposals regarding other business to be conducted at a special or annual meeting, the 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 acquiror from conducting a solicitation of proxies to elect its own slate of directors or otherwise attempting to obtain control of the company.

The DGCL generally provides that the affirmative vote of a majority of the shares entitled to vote on any matter is required to amend a corporation's certificate of incorporation or bylaws, unless either a corporation's certificate of incorporation or bylaws requires a greater percentage. Our Certificate of Incorporation provides that the affirmative vote of holders of at least 75% of the total votes eligible to be cast in the election of directors will be required to amend, alter, change or repeal any provisions of our Bylaws and specified provisions of our Certificate of Incorporation. This requirement of a supermajority vote to approve amendments to our Certificate of Incorporation and Bylaws could enable a minority of our securityholders to exercise veto power over any such amendments.

Our authorized but unissued shares of common stock and preferred stock are available for future issuance without securityholder approval. These additional shares may be utilized for a variety of corporate purposes, including future public offerings to raise additional capital, corporate acquisitions and employee benefit plans. The existence of authorized but unissued shares of common stock and preferred stock could render it 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.

We have elected in our Certificate of Incorporation not to be subject to Section 203 of the DGCL, an antitakeover law. In general, Section 203 prohibits a publicly held Delaware corporation from engaging in a business combination, such as a merger, with a person or group owning 15% or more of the corporation's voting stock for a period of three years following the date the person became an interested securityholder, unless (with certain exceptions) the business combination or the transaction in which the person became an interested securityholder is approved in a prescribed manner. Accordingly, we are not subject to any anti-takeover effects of Section 203. However, our Certificate of Incorporation contains provisions that have the same effect as Section 203.