This is a sole-source notice for 2 units of NSN 7R-5895-017316503-RQ, with delivery FOB Origin. The government intends to negotiate with only one source because the technical data is unavailable and the item is flight-critical, requiring prior source approval. Only previously approved sources have been solicited, and new sources must submit detailed approval information per the NAVSUP WSS Source Approval Brochure. Proposals from all responsible sources will be considered if received within 45 days of this notice's publication. No budget amount or performance location is specified.