A device used to prevent passage of flame through a ventilating duct while air is flowing.
NSN 4140-00-170-5152
NSN 6685-01-463-8461
NSN 5835-01-632-6627
NSN 5910-01-630-0832
NSN 5945-01-352-5705
NSN 4140-01-152-4199
NSN 6110-01-335-9192
NSN 7035-01-284-5043
NSN 5915-01-467-1630
NSN 5935-00-031-0610
NSN 6110-01-021-0199
NSN 5985-01-373-6492