The requirement is for 50 pairs of NSN 3H-3110-009921019-NT, TDP version 007, with delivery FOB origin. The part requires engineering source approval by the design control activity; approved sources retain data rights, manufacturing/repair knowledge, or technical data not economically available to the Government, and any alternate source must qualify under procedures approved by the cognizant Government engineering activity. Specifications and standards are available through DODSSP/DAPS in Philadelphia and ASSIST-Online, but patterns, drawings, deviation lists, and purchase descriptions are not stocked at DODSSP. The Government is not using FAR Part 12 commercial-item policies, though interested parties may identify commercial-item interest and capability to the contracting officer.