3 inch diameter; stainless (1615ss)
A device used to prevent passage of flame through a ventilating duct while air is flowing.
NSN 5910-01-502-5860
NSN 5895-00-623-3145
NSN 6220-00-925-2233
NSN 5915-00-587-0560
NSN 6685-00-252-3057
NSN 6620-01-586-3456
NSN 6620-00-181-6391
NSN 6240-01-540-5980
NSN 5920-01-120-5093
NSN 5895-00-896-0503
NSN 6110-01-026-1236
NSN 6645-01-538-9655