Okla. Stat. tit. 12A, § 12A-2-207: Additional Terms in Acceptance or Confirmation

(1) A definite and seasonable expression of acceptance or a

written confirmation which is sent within a reasonable time operates

as an acceptance even though it states terms additional to or

different from those offered or agreed upon, unless acceptance is

expressly made conditional on assent to the additional or different

terms.

(2) The additional terms are to be construed as proposals for

addition to the contract. Between merchants such terms become part

of the contract unless:

(a) the offer expressly limits acceptance to the terms of

the offer;

(b) they materially alter it; or

(c) notification of objection to them has already been

given or is given within a reasonable time after notice of them is

received.

(3) Conduct by both parties which recognizes the existence of a

contract is sufficient to establish a contract for sale although the

writings of the parties do not otherwise establish a contract. In

such case the terms of the particular contract consist of those

terms on which the writings of the parties agree, together with any

supplementary terms incorporated under any other provisions of this

act.