Terms with respect to which the confirmatory memoranda of the parties agree or which are otherwise set forth in a record intended by the parties as a final expression of their agreement with respect to such terms as are included therein may not be contradicted by evidence of any prior agreement or of a contemporaneous oral agreement but may be explained or supplemented:
Okla. Stat. tit. 12A, § 2A-202
Oklahoma Code Comment
This section displaces for leases of goods the general provisions of 16 Oklahoma Statutes §§ 137 and 166. It is doubtful, however, that the results of any cases will be altered. For example, see Albert & Harlow, Inc. v. Fitzgerald, 389 P.2d 994 ((Okla.1964)) (evidence of asserted right to return leased property after 60 days when lease provided a minimum rental period of 90 days is excluded).
The 1991 amendments make no change here.