This requirement is for 13 units of an NSN item with delivery FOB origin. The item is flight critical and requires engineering source approval; only government-approved sources are being solicited. An alternate source must qualify through government-approved procedures, and if not already approved, must submit all required source approval data with an offer. The government intends to solicit and negotiate with only one source under FAR 6.302-1, but all responsible sources may express interest or submit capability statements. This is not a commercial item acquisition.