Used to hang fixtures. Cover accepts devices with mounting screw centers of 2 3/4, 3 1/2, and 4 1/16 (70mm, 89mm, and 103mm). Base has four holes for fixture studs, four 1/2 trade size KOs, and raised section for no-bolt fixture-stud. Use as a junction or pull box with 5736 Blank Cover. Outside diameter 4 3/4 (121mm). NOTE: Certified to Canadian Safety Standards for sale in Canada. When ordering these products, change the V color prefix to VC or the WH color suffix to WHC to denote the Canadian versions. White