A device used to prevent passage of flame through a ventilating duct while air is flowing.
NSN 6610-01-310-3313
NSN 6320-01-166-3602
NSN 6220-01-301-2329
NSN 5990-01-061-5618
NSN 6145-00-515-6931
NSN 6645-01-089-6459
NSN 5985-01-396-9422
NSN 2925-01-297-2315
NSN 7035-01-182-1086
NSN 5999-01-247-3359
NSN 4140-01-224-6994
NSN 5915-01-262-4771