This procurement is restricted to government-approved sources for a flight-critical item because adequate technical data for competitive acquisition is unavailable. Only previously approved sources are solicited, and any new source must submit a complete Source Approval Brochure detailing its production experience; offers lacking this documentation will be rejected. Interested parties may identify their capability to supply a commercial item alternative within 15 days of this notice. The requirement is for 8 units with delivery FOB origin.