Okla. Stat. tit. 12A, § 12A-2-205: Firm Offers

An offer by a merchant to buy or sell goods in a signed record

which by its terms gives assurance that it will be held open is not

revocable, for lack of consideration, during the time stated or if

no time is stated for a reasonable time, but in no event may such

period of irrevocability exceed three (3) months; but any such term

of assurance on a form supplied by the offeree must be separately

signed by the offeror.