A device used to prevent passage of flame through a ventilating duct while air is flowing.
NSN 6620-01-552-2889
NSN 6645-01-089-6459
NSN 6645-00-806-6961
NSN 5945-00-398-1072
NSN 6130-01-634-0603
NSN 6650-00-850-3312
NSN 6610-01-280-3429
NSN 6135-01-595-9328
NSN 2925-00-845-1480
NSN 5895-00-112-8767
NSN 6150-01-125-3016
NSN 2925-01-471-3365