1-1/2" deep, 4" square drawn boxes with (6) 1/2" & (6) 1/2"-3/4" side knockouts and open back with mounting tabs and 8-32 screws are installed in walls or ceilings for lighting fixtures, switches, receptacles or other outlet devices. Dual "back door" access extension rings allow entry to devices, wires and wire nuts after they have been installed on plaster rings. Blank covers enclose wires in rings and attach to the bottom tapped 8-32 ears. Square boxes are used to bring \ power to a number of electrical devices where multiple conductor runs are split in two or more directions. Garvin Industries’ 4S Boxes can be surface or flush mounted when multi directional conduit runs are necessary.