This is a sole-source procurement under FAR 6.302-1 for one unit of a flight-critical NSN 7R-1560-017355849-E7 part (ref 123GSR6-304), FOB origin. The item requires Government engineering source approval by the design control activity, and only previously approved sources have been solicited because they retain essential design, manufacturing, or repair knowledge and data rights. New sources must qualify under the design control activity’s procedures and submit the NAVSUP WSS Source Approval Information Brochure data with their proposal; offers lacking required data will not be considered. If source approval cannot be completed in time, award may proceed based on Fleet support needs. Drawings are not available, FAR Part 12 commercial-item procedures are not being used, and responsible sources may identify interest/capability or submit proposals, though this notice is not a request for competitive proposals.