A device used to prevent passage of flame through a ventilating duct while air is flowing.
NSN 6110-01-071-2726
NSN 5990-01-649-4647
NSN 5990-01-465-8031
NSN 6685-01-199-1304
NSN 5945-00-880-5426
NSN 7035-00-020-2227
NSN 5985-00-765-1421
NSN 4140-00-451-8374
NSN 6110-00-172-6126
NSN 6240-01-322-5521
NSN 5855-00-011-5816
NSN 6645-01-287-9969