A device used to prevent passage of flame through a ventilating duct while air is flowing.
NSN 6135-01-029-9315
NSN 4140-00-103-2449
NSN 6145-00-511-9705
NSN 6320-01-612-7035
NSN 6620-01-039-5468
NSN 5930-01-083-5807
NSN 5945-00-114-7687
NSN 6150-01-278-9269
NSN 5835-01-115-6067
NSN 5910-00-121-6276
NSN 5925-00-114-2253
NSN 6685-00-191-3214