A device used to prevent passage of flame through a ventilating duct while air is flowing.
NSN 5905-01-421-4157
NSN 6220-01-242-3799
NSN 6150-01-273-2627
NSN 5855-00-221-9435
NSN 2925-00-596-9775
NSN 6685-00-432-3576
NSN 2925-00-295-8109
NSN 5930-00-277-4704
NSN 5960-00-515-7366
NSN 4140-01-362-5992
NSN 6150-01-042-4942
NSN 5915-01-258-4911