A device used to prevent passage of flame through a ventilating duct while air is flowing.
NSN 5975-00-777-8171
NSN 4140-01-027-1871
NSN 5910-01-476-7272
NSN 5855-01-364-1005
NSN 6240-00-393-1161
NSN 6610-01-023-1812
NSN 6650-01-071-7985
NSN 6240-01-626-9055
NSN 5930-01-337-5426
NSN 5999-01-025-9717
NSN 6145-00-901-3876
NSN 6610-01-171-3010