A device used to prevent passage of flame through a ventilating duct while air is flowing.
NSN 5996-01-599-2369
NSN 4140-01-064-6474
NSN 5930-01-236-8368
NSN 5999-01-027-5708
NSN 5960-00-622-2149
NSN 6685-00-120-1009
NSN 5965-01-376-8887
NSN 6240-00-964-3728
NSN 6685-00-807-8328
NSN 5930-01-378-6832
NSN 5960-01-215-9232
NSN 6620-01-435-7083