A device used to prevent passage of flame through a ventilating duct while air is flowing.
NSN 5925-01-384-3065
NSN 6650-01-016-0406
NSN 5960-01-201-5804
NSN 5999-00-593-8134
NSN 6240-01-251-8435
NSN 5925-01-421-5731
NSN 5950-01-068-3144
NSN 6130-01-037-5127
NSN 6150-01-045-0056
NSN 5930-01-509-2432
NSN 5935-01-192-4428
NSN 6650-00-408-4972