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 5835-01-307-8954
NSN 7035-01-033-3007
NSN 6130-00-180-5149
NSN 5965-01-021-4163
NSN 5990-01-168-0820
NSN 5998-00-452-0329
NSN 5930-01-261-6790
NSN 5835-00-034-4976
NSN 5985-01-364-9609
NSN 5965-01-260-0780
NSN 5985-01-200-7497
NSN 6240-01-577-1964