This requirement is for NSN 7R-2840-015911511-SX, quantity 4, with delivery FOB origin. The item is flight critical and requires engineering source approval from the design control activity; only previously approved sources have been solicited. New sources must submit all required technical data as specified in the NAVSUP WSS Source Approval Information Brochure, or their offers will not be considered. Award will be made only if the offeror or manufacturer meets the qualification requirement at the time of award per FAR 52.209-1. The Government is not using commercial item acquisition policies for this procurement.