A device used to prevent passage of flame through a ventilating duct while air is flowing.
NSN 5930-01-113-7828
NSN 6610-00-143-7384
NSN 5915-01-597-3926
NSN 5935-01-459-0444
NSN 5905-01-378-7224
NSN 5935-01-642-0451
NSN 5996-01-590-9918
NSN 2925-01-459-8093
NSN 5925-01-298-7163
NSN 6685-01-571-0808
NSN 6105-00-383-2984
NSN 7035-01-186-0024