A rigid item designed to frame a structural opening for reinforcement purposes and/or to accommodate covers, access (as modified) and doors, access (as modified).
NSN 6685-01-183-2890
NSN 5925-00-636-5683
NSN 5915-01-560-2307
NSN 6110-00-106-6587
NSN 6645-00-434-8793
NSN 5910-01-603-6017
NSN 5915-01-364-2251
NSN 5925-00-581-6021
NSN 6685-00-897-2104
NSN 5920-01-013-8594
NSN 6135-00-505-0679
NSN 5950-01-224-2619