A device used to prevent passage of flame through a ventilating duct while air is flowing.
NSN 5905-01-647-6342
NSN 6240-01-435-7973
NSN 6220-01-034-1231
NSN 5855-01-597-8638
NSN 6145-01-044-5278
NSN 6685-01-563-4726
NSN 5935-00-851-0270
NSN 5905-00-299-1831
NSN 6320-01-592-6248
NSN 6240-01-232-8079
NSN 5935-00-238-2044
NSN 5895-00-008-6988