A device used to prevent passage of flame through a ventilating duct while air is flowing.
NSN 5895-01-449-8433
NSN 5930-00-740-8600
NSN 6645-00-727-5119
NSN 5960-01-191-1982
NSN 5925-01-308-8548
NSN 6240-01-016-8140
NSN 5990-00-033-8128
NSN 6145-00-267-9617
NSN 6645-01-195-6207
NSN 5910-01-647-1130
NSN 4140-01-095-2719
NSN 5920-00-102-8713