Six 1/2 in and 3 TKO conduit knockouts (sides). Three 1/2 in and 2 TKO conduit knockouts (bottom). Combination cover screw heads provide for faster mud ring/cover installation. FM bracket mounts flat on side of stud and provides a rigid, secure box installation. Square boxes are installed in ceiling or walls for lighting fixture or receptacles. 4 in square x 1-1/2 in D. 21 cu-in. UPC bar code. UL listed.