A device used to prevent passage of flame through a ventilating duct while air is flowing.
NSN 5996-00-971-0702
NSN 6685-00-361-9797
NSN 6320-01-543-3238
NSN 5965-00-682-3567
NSN 5975-01-634-0678
NSN
NSN 5925-00-647-3469
NSN 5990-00-140-4559
NSN 5925-01-407-2061
NSN 6620-01-207-0667
NSN 5990-01-431-3725
NSN 5960-01-226-0342