A device used to prevent passage of flame through a ventilating duct while air is flowing.
NSN 5975-01-188-7460
NSN 6110-01-184-5560
NSN 5975-00-833-6983
NSN 6610-00-186-9180
NSN 5835-00-251-9138
NSN 6645-01-317-1308
NSN 5960-01-144-9183
NSN 6610-01-178-5435
NSN 5910-01-642-0467
NSN 5925-01-123-3716
NSN 5998-00-420-1448
NSN 5930-01-327-0250