An item with an integral porous or perforated plate, or with slits on the inside of a double wall.
NSN 6145-00-244-4360
NSN 6645-01-254-0489
NSN 5999-01-335-2757
NSN 5985-00-808-3051
NSN 5990-01-387-0623
NSN 5999-00-648-9107
NSN 5895-00-899-0334
NSN 6240-01-590-1347
NSN 6240-01-641-9347
NSN 6130-01-173-8855
NSN 6240-01-031-5505
NSN 5985-01-076-5094