EXHIBIT 3.1.5

                          CERTIFICATE OF INCORPORATION

                                       OF

                       ESSEX ACQUISITION SUBSIDIARY, INC.

                                   ARTICLE I

         The name of the Corporation is Essex Acquisition Subsidiary, Inc. (the
"Corporation").

                                   ARTICLE II

         The address of the Corporation's registered office in the State of
Delaware is 1209 Orange Street, City of Wilmington, County of New Castle,
Delaware 19801. The name of its registered agent at such address is The
Corporation Trust Company.

                                  ARTICLE III

         The purpose of the Corporation is to engage in any lawful act or
activity for which a corporation may be organized under the General Corporation
Law of the State of Delaware.

                                   ARTICLE IV

         The Corporation is authorized to issue one class of capital stock to be
designated "Common Stock", with a par value of $0.001 per share. The total
number of shares which the Corporation is authorized to issue is 20,000,000,
consisting of 17,000,000 shares of Class A Common Stock, and 3,000,000 shares of
Class B Common Stock.

         The relative rights, preferences, privileges and restrictions granted
to or imposed upon the respective classes of the shares of capital stock or the
holders thereof are as set forth below.

                                   ARTICLE V

         Except as otherwise provided in this Article V, the rights, preferences
and limitations of Class A Common Stock and Class B Common Stock shall be
identical in all respects:

         1.       Voting Rights. Each holder of Class A Common Stock shall have
the right to one vote in respect of each share of Class A Common Stock held by
him or her and shall be entitled to vote upon all matters and in such manner as
may be provided by law. The holders of Class B Common Stock shall have no voting
powers except as required by law provided herein.

                                   ARTICLE VI

         The Corporation reserves the right to amend, alter, change, or repeal
any provision contained in this Certificate of Incorporation, in the manner now
or hereafter prescribed by the statute, and all rights conferred upon the
stockholder herein are granted subject to this right.



                                  ARTICLE VII

         The Corporation is to have perpetual existence.

                                  ARTICLE VIII

         1.       Limitation of Liability. To the fullest extent permitted by
the General Corporation Law of the State of Delaware as the same exists or as
may hereafter be amended, a director of the Corporation shall not be personally
liable to the Corporation or its stockholders for monetary damages for breach of
fiduciary duty as a director.

         2.       Indemnification. The Corporation may indemnify to the fullest
extent permitted by law any person made or threatened to be made a party to an
action or proceeding, whether criminal, civil, administrative or investigative,
by reason of the fact that such person or his or her testator or intestate is or
was a director, officer of employee of the Corporation, or any predecessor of
the Corporation, or serves or served at any other enterprise as a director,
officer or employee at the request of the Corporation or any predecessor to the
Corporation.

                                   ARTICLE IX

         Holders of voting stock of any class or series of the Corporation shall
not be entitled to cumulate their votes for the election of directors or any
other matter submitted to a vote of the stockholders, unless such cumulative
voting is required pursuant to Sections 2115 and/or 301.5 of the California
Corporations Code, in which event each such holder shall be entitled to as many
votes as shall equal the number of votes which (except for this provision as to
cumulative voting) such holder would be entitled to cast for the election of
directors with respect to his shares of stock multiplied by the number of
directors to be elected by him, and the holder may cast all of such votes for a
single director or may distribute them among the number of directors to be voted
for, or for any two or more of them as such holder may see fit, so long as the
name of the candidate for director shall have been placed in nomination prior to
the voting and the stockholder, or any other holder of the same class or series
of stock, has given notice at the meeting prior to the voting of the intention
to cumulate votes.

                                   ARTICLE X

         1.       Number of Directors. The number of directors which constitutes
         the whole Board of Directors of the Corporation shall be designated in
         the Bylaws of the Corporation.

         2.       Election of Directors. Elections of directors need not be by
         written ballot unless the Bylaws of the Corporation so provide.

                                   ARTICLE XI

         In furtherance and not in limitation of the powers conferred by
statute, the Board of Directors is expressly authorized to make, alter, amend or
repeal the Bylaws of the Corporation.

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                                   ARTICLE XII

         The name and mailing address of the incorporator are:

                                  Gustavo Casas
                        Wilson Sonsini Goodrich & Rosati
                               650 Page Mill Road
                               Palo Alto, CA 94304

         The undersigned incorporator hereby acknowledges that the above
Certificate of Incorporation of Moose Acquisition Subsidiary, Inc. is his act
and deed and that the facts stated therein are true.

Dated:  May 30, 2000

                                                   /s/ Gustavo Casas
                                                   ---------------------------
                                                   Gustavo Casas, Incorporator

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