41 U.S.C. § 103

In this subtitle, the term “commercial product” means any of the following: (1) A product, other than real property, that— (A) is of a type customarily used by the general public or by nongovernmental entities for purposes other than governmental purposes; and (B) has been sold, leased, or licensed, or offered for sale, lease, or license, to the general public. (2) A product that— (A) evolved from a product described in paragraph (1) through advances in technology or performance; and (B) is not yet available in the commercial marketplace but will be available in the commercial marketplace in time to satisfy the delivery requirements under a Federal Government solicitation. (3) A product that would satisfy the criteria in paragraph (1) or (2) were it not for— (A) modifications of a type customarily available in the commercial marketplace; or (B) minor modifications made to meet Federal Government requirements. (4) Any combination of products meeting the requirements of paragraph (1), (2), or (3) that are of a type customarily combined and sold in combination to the general public. (5) A product, or combination of products, referred to in paragraphs (1) through (4), even though the product, or combination of products, is transferred between or among separate divisions, subsidiaries, or affiliates of a contractor. (6) A nondevelopmental item if the procuring agency determines, in accordance with conditions in the Federal Acquisition Regulation, that— (A) the product was developed exclusively at private expense; and (B) has been sold in substantial quantities, on a competitive basis, to multiple State and local governments or to multiple foreign governments.