A device used to prevent passage of flame through a ventilating duct while air is flowing.
NSN 5895-01-358-0515
NSN 5945-01-384-3735
NSN 6130-00-152-9378
NSN 6145-00-793-7816
NSN 5990-01-485-0260
NSN 5975-01-339-1380
NSN 5999-00-584-0830
NSN 6135-00-994-5021
NSN 5965-01-578-6081
NSN 6105-01-474-5246
NSN 5930-01-453-8417
NSN 4140-01-270-6246