The Government seeks 26 each of NSN 0R-5821-200118711-QF (ref 152505-1), FOB origin, for a flight-critical part whose current design is unstable and expected to become obsolete pending configuration changes, with limited acquisition/repair from the present source anticipated. Government source approval is required before award; only previously approved sources have been solicited, and new-source approval normally cannot be completed in time to avoid delaying award. Non-approved sources must submit the NAVSUP WSS Source Approval Brochure data with their proposal, and offers lacking required data or prior submission documentation will not be considered. The action is intended as a sole-source negotiation under FAR 6.302-1, though responsible sources may identify interest/capability or submit proposals; this is not a request for competitive proposals and the competition determination is discretionary. FAR Part 12 commercial-item policies are not being used, but interested parties may identify commercial-item interest/capability to the contracting officer; standardized documents are available via DODSSP in Philadelphia, PA, or ASSIST-Online.