3 inch diameter; stainless (1615ss)
A device used to prevent passage of flame through a ventilating duct while air is flowing.
NSN 2925-01-446-6976
NSN 5915-00-728-5577
NSN 5925-01-372-6478
NSN 6220-00-682-8292
NSN 6645-01-058-1506
NSN 5910-00-232-5028
NSN 5835-01-092-6759
NSN 5930-01-400-6126
NSN 2925-01-483-2389
NSN 5990-01-572-3137
NSN 5905-00-203-2182
NSN 6110-01-441-1623