This is a procurement for a flight-critical commercial/nondevelopmental item requiring Government source approval prior to award, with only previously approved sources solicited. New sources must submit the required source approval information as detailed in the NAVSUP WSS brochures, or their offers will not be considered. Interested parties may express their capability to supply a commercial item within 15 days of this notice. The quantity is 4 units with delivery FOB origin. No budget amount or performance location is specified.