Boxes are installed in ceilings or walls for lighting fixtures or receptacles For steel studs, the Box-Loc bracket mounts on either side of any depth stud Extension rings provide a means for adding additional cubic capacity or as an outlet box for surface conduit Quick installation on flat side of metal or wood studs 1/8-in gauging tabs locate the box flush with the face of the stud in perfect position for a plaster, mud, ring Bracket 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 installation Combination screw heads provide for faster installation Box may serve as fixture support for fixtures up to 50 lbs 1/2-in knock outs 4-in x 1-1/2-in