5965-01-124-1817 (21581-1)
NSN 5965-01-124-1817 (NIIN 01-124-1817) is an acoustical filter in Federal Supply Class 5965, Headsets, Handsets, Microphones And Speakers — an item specifically designed to absorb certain audio frequencies. Manufacturer part number 21581-1 (Astrocom Electronics Inc, CAGE 18068).
NIIN assigned December 1981; DEMIL A (none required); export Schedule B 8518.90.3000.