A device used to prevent passage of flame through a ventilating duct while air is flowing.
NSN 6220-01-497-7229
NSN 6130-01-538-5432
NSN 5935-01-303-3092
NSN 6110-01-248-4197
NSN 5990-01-411-7706
NSN 5835-01-090-0784
NSN 5999-01-049-0368
NSN 6130-01-101-7029
NSN 5960-01-502-6270
NSN 5960-00-491-7356
NSN 5999-00-835-8745
NSN 5990-01-472-2447