The requirement is for 4 each of a commercial/nondevelopmental/off-the-shelf, flight-critical item, delivered FOB origin, with Government source approval required before contract award. Only previously approved sources have been solicited, and new sources must include with their offer the information required by the applicable NAVSUP WSS Source Approval Brochure or evidence that all required data were previously submitted. Offers lacking the required source-approval data will not be considered, and source-approval processing is normally too lengthy to delay award pending a new source. If approval cannot be completed in time or approval requirements prevent timely delivery, award may still proceed based on Fleet support needs. Award requires the offeror, product/service, or manufacturer to meet qualification requirements at time of award under FAR 52.209-1, with standardized documents available through DODSSP/ASSIST.