A device used to prevent passage of flame through a ventilating duct while air is flowing.
NSN 6610-01-037-4392
NSN 6150-01-071-1498
NSN 5910-01-502-8643
NSN 6645-01-142-1707
NSN 6110-00-834-0595
NSN 6110-01-276-2120
NSN 6150-00-401-6027
NSN 5835-00-494-8419
NSN 6110-01-174-4422
NSN 5915-01-446-9492
NSN 6220-01-556-6330
NSN 5935-01-466-7559