Final expression: parol or extrinsic evidence [UCC 2A-202]
Terms with respect to which the confirmatory memoranda of the parties agree or that otherwise are set forth in a record intended by the parties as a final expression of their agreement with respect to the terms that are included in their agreement may not be contradicted by evidence of any prior agreement or of a contemporaneous oral agreement but may be explained or supplemented by both of the following:
(A) Course of dealing, usage of trade, or course of performance;
(B) Evidence of consistent additional terms, unless the court finds the record to have been intended also as a complete and exclusive statement of the terms of the agreement.