3M ZMO housing is a 3-piece, all metal, industrial quality housing, which uses 222 plug-in style O-ring seal cartridges. It is a non-code housing, with 1 in NPT inlet/outlet, Buna N nitrile O-ring and has a maximum operating pressure and temperature 150 psi at 200 deg F (housing only, actual filter operating temperature depends on the temperature capability of the filter cartridge). The 3M ZMO housing is constructed of 316 stainless steel head, sump, vent and drain plugs. The housing features a single, 302 stainless steel V-band clamp for ease in cartridge change out. 1ZMO1 (1-high) is sized for a 10 in filter cartridge, 1ZMO2 (2-high) sized for a 20 in filter cartridge and 1ZMO3 (3-high) sized for a 30 in filter cartridge.