This is a sole-source intent under FAR 6.302-1 for a flight-critical item (quantity 20 EA, FOB origin) requiring Government engineering source approval by the design control activity; only previously approved sources have been solicited. Approved sources retain essential design, manufacturing/repair, or technical data that are not economically available to the Government, and alternate sources must qualify through the cognizant Government engineering activity. Non-approved sources must submit the NAVSUP WSS Source Approval Information Brochure data with their offer, and offers missing required data or prior submission documentation will not be considered. If source approval cannot be processed in time or approval requirements prevent timely delivery, award may proceed based on Fleet support needs.