YNB1003 Features: * Octagon extension ring * Boxes are used in the installation of ceiling or wall lighting fixtures * Provide a means for adding additional cubic capacity or as an outlet box for surface conduit * Combination screw heads provide for faster installation * Time-saving set-up boxes shorten installation time for lighting fixtures * Two 0.5" and two 0.75" side knockouts * Octagon boxes are used in the installation of ceiling or wall lighting fixtures * Some covers may serve as fixture support for fixtures up to 50 lbs * UL - File E195978 * CSA - File LR-1082 (128, 130, 131RAC) * 15.5 Cubic inches capacity Dimensions: * Dimensions: 4" H x 4" W x 1.56" D