A device used to prevent passage of flame through a ventilating duct while air is flowing.
NSN 6620-01-645-4148
NSN 5990-00-659-8067
NSN 5930-00-769-4998
NSN 5895-01-339-4472
NSN 5998-00-156-3119
NSN 6105-01-407-7139
NSN 5996-00-222-6049
NSN 6240-01-324-5222
NSN 5855-00-252-5743
NSN 5935-01-153-2662
NSN 5905-01-577-4116
NSN 5945-01-417-2146