A device used to prevent passage of flame through a ventilating duct while air is flowing.
NSN 5855-01-435-5548
NSN 5996-01-486-2045
NSN 6150-01-457-7827
NSN 5996-00-733-5690
NSN 5895-00-593-0524
NSN 7035-00-938-8289
NSN 5930-00-278-7731
NSN 6685-01-258-3218
NSN 5950-01-322-7948
NSN 6620-01-531-3250
NSN 6685-00-105-9896
NSN 6135-00-120-1034