A device used to prevent passage of flame through a ventilating duct while air is flowing.
NSN 6320-01-326-1316
NSN 6650-01-036-3498
NSN 6610-00-100-1195
NSN 6145-00-454-0566
NSN 6105-01-497-9897
NSN 5905-01-650-9952
NSN 6150-01-498-1737
NSN 5998-01-363-8364
NSN 5960-00-827-1201
NSN 6220-01-097-1212
NSN 5935-01-146-7723
NSN 6240-01-630-2702