This is a sole-source procurement for a flight-critical part that requires Government source approval prior to contract award, with only previously approved sources solicited. Any new source must submit the detailed data required by the NAVSUP WSS Source Approval Information Brochure, and offers lacking that documentation will not be considered. Because approval of a new source typically cannot be completed in time, award may proceed based on Fleet support needs even if a source approval request is pending. The Government intends to negotiate with only one source under FAR 6.302-1, but all responsible parties may express interest or submit capability statements, with the possibility of a future competitive procurement. No budget amount or performance location is specified; delivery is FOB origin.