Square Boxes and Extension Rings are manufactured from durable pre-galvanized steel and are designed to house and protect electrical wiring, switches, receptacles and to support light fixtures. All steel boxes are UL listed and acceptable for use in 2-hour fire rated walls and ceilings. 8-32 fixture mounting screws are assembled. 2 -1/8 in DeepWelded with Conduit KO'sRaised GroundBracket is longer and wider than standard bracket to assure a rigid installation and to help prevent the box from being pushed into the wall during drywall installationCombination screw heads provide for faster installationRaco boxes may serve as fixture support for fixtures up to 50 pounds1/2" knockouts