Used to hang light fixtures between joists or structural members. Includes 3-1/2 inch round box. Not designed for ceiling fan support. RACO nonmetallic cable boxes provide the installer with a cost alternative that is lightweight and easy to install. Self clamping wire entry clamps. Bar hanger adjustable from 14-3/4 inch to 22-1/2 inch. When mounted, box is flush with ceiling surface. 1/2 inch set back.