commodities and commodity indices over the term of the Notes.  The basket will be comprised of 10 commodities and two commodity indices, with each commodity or index having the following weightings:  Aluminum — 7%; Copper — 7%; Crude Oil — 15%; Gold — 5%; Heating Oil — 5%; Lead — 5%; Natural Gas — 10%; Nickel — 6%; Unleaded Gasoline — 5%; Zinc — 5%; GSCI Agriculture Excess Return Index — 20%; and GSCI Livestock Excess Return Index — 10%.

Redemption Amount: The redemption amount at maturity will equal the principal amount of the Notes multiplied by the sum of 1 plus the basket return, calculated as set forth in the pricing supplement for the Notes.  If the final basket level is greater than the initial basket level, the basket return will be equal to the percentage increase in the basket level multiplied by 180%.  If the final basket level is less than or equal to the initial basket level, then the basket return will be equal to zero, and the redemption amount will be an amount equal to the principal amount of the Notes at maturity, as further explained in the pricing supplement for the Notes.

Optional Redemption: None.

Sinking Fund: None.

Listing: None.

Trade Date :  December 16, 2005

Settlement Date :  December 21, 2005

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Details for Settlement

Book-entry Security

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Unless the undersigned has received notification from the Issuer within one Business Day (as defined in the Distribution Agreement) that the Issuer does not agree to the terms set forth herein, this Terms Agreement shall constitute an agreement between the Issuer and the undersigned for the sale and purchase of the Notes upon the terms set forth herein and in the Distribution Agreement.

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CREDIT SUISSE FIRST BOSTON (USA), INC.

SUPPLEMENT TO DISTRIBUTION AGREEMENT

1.     Scope.   This Supplement is attached to and forms a part of the Terms Agreement, dated December 16, 2005  (including the Distribution Agreement (as defined in the Terms Agreement) incorporated by reference therein, the “Terms Agreement” ), between Credit Suisse First Boston (USA), Inc., a  Delaware corporation ( “Issuer” ), and the Distributor (as defined therein).  References in the Terms Agreement to “herein” and “hereof” include the provisions of this Supplement.  In the event of any conflict between the Terms Agreement and this Supplement, the provisions of this Supplement shall control.  Capitalized terms used but not defined herein have the meanings ascribed in the Terms Agreement.

2.     Definitions.   The following terms have the following meanings in this Supplement and the Terms Agreement:

(a)     “Registration Statement” as of any time means the Registration Statement (as defined in the Distribution Agreement) in the form then filed with the Commission, including any document incorporated by reference therein and any prospectus, prospectus supplement or pricing supplement deemed or retroactively deemed to be a part thereof that has not been superseded or modified.  “Registration Statement” without reference to a time means the Registration Statement as of the time of the first contract of sale for the Notes, which time shall be considered the “effective date” of the Registration Statement.   For purposes of this definition, information contained in a form of prospectus,  prospectus supplement or pricing supplement that is deemed retroactively to be a part of the Registration Statement pursuant to Rule 430B shall be considered to be included in the Registration Statement as of the time specified in Rule 430B.

(b)     “Statutory Prospectus” as of any time means the prospectus and prospectus supplement relating to the Notes that is included in the Registration Statement immediately prior to that time, including any document incorporated by reference therein and any basic prospectus or prospectus supplement deemed to be a part thereof that has not been superseded or modified.  For purposes of this definition, information contained in a form of prospectus or prospectus supplement (including a pricing  supplement) that is deemed retroactively to be a part of the Registration Statement pursuant to Rule 430B or 430C shall be considered to be included in the Statutory Prospectus only as of the actual time that form of prospectus or prospectus supplement (including a pricing supplement) is filed with the Commission pursuant to Rule 424(b).

(c)     “Prospectus” means the Statutory Prospectus that discloses the public offering price and other final terms of the Notes and otherwise satisfies Section 10(a) of the Securities Act of 1933.

(d)   “Issuer Free Writing Prospectus” means any “issuer free writing prospectus,” as defined in Rule 433, relating to the Notes in the form filed or required to be filed with the Commission or, if not required to be filed, in the form retained in the Issuer’s records pursuant to Rule 433(g), if any.

(e)     “General Use Issuer Free Writing Prospectus” means any Issuer Free Writing Prospectus that is intended for general distribution to prospective investors, as e