An item with an integral porous or perforated plate, or with slits on the inside of a double wall.
NSN 5930-01-211-9909
NSN 6645-01-605-8796
NSN 5915-01-202-6336
NSN 5920-00-050-0599
NSN 5915-01-195-9871
NSN 5855-01-060-8521
NSN 6110-01-144-2832
NSN 6645-01-215-0617
NSN 5905-01-551-6608
NSN 6240-01-465-3053
NSN 5975-00-290-4285
NSN 5965-01-350-5105