2-1/8" deep, 4" square welded boxes with air tight (4) 1" & (4) 3/4" side knockouts and (2) 1/2" & (2) 3/4" bottom knockouts are installed in walls or ceilings for lighting fixtures, switches, receptacles or other outlet devices. 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.