48 CFR § 12.402 - Acceptance.
(a) The acceptance paragraph in 52.212–4 is based upon the assumption that the Government will rely on the contractor's assurances that the commercial product or commercial service tendered for acceptance conforms to the contract requirements. The Government inspection of commercial products or commercial services will not prejudice its other rights under the acceptance paragraph. Additionally, although the paragraph does not address the issue of rejection, the Government always has the right to refuse acceptance of nonconforming items. This paragraph is generally appropriate when the Government is acquiring noncomplex commercial products and commercial services.
(b) Other acceptance procedures may be more appropriate for the acquisition of complex commercial products or commercial services, or commercial products or commercial services used in critical applications. In such cases, the contracting officer shall include alternative inspection procedure(s) in an addendum and ensure these procedures and the postaward remedies adequately protect the interests of the Government. The contracting officer must carefully examine the terms and conditions of any express warranty with regard to the effect it may have on the Government's available postaward remedies (see 12.404).
(c) The acquisition of commercial products or commercial services under other circumstances such as on an “as is” basis may also require acceptance procedures different from those contained in 52.212–4. The contracting officer should consider the effect the specific circumstances will have on the acceptance paragraph as well as other paragraphs of the clause.