F-F-2790, FEDERAL SPECIFICATION: FILTER, AIR-EXTENDED AREA, INITIAL INSTALLATION (27-NOV-1991) [S/S BY A-A-50554]

F-F-2790, FEDERAL SPECIFICATION: FILTER, AIR-EXTENDED AREA, INITIAL INSTALLATION (27-NOV-1991) [S/S BY A-A-50554]., This specification covers replaceable, extended media area type air filters with externally supported, nonsupported, or self-supporting cartridges installed in permanent metal holding frames and housings as required for use in air conditioning, heating, and ventilating systems.