Ceiling fan box, 4 in octagon, 1-1/2 in deep. 15.5 cubic inch capacity. 4 side and 3 bottom 1/2 in knockouts. Used in new work and renovations. Ceiling fan rated octagon boxes can be used in the installation of heavy light fixtures or ceiling fans. Recommendedsupport load for ceiling fan is 70 pounds, for fixtures is 150 pounds. Includes non-metallic sheathed cable connector, mounting hardware, high strength hardened screws, and instructions. Acceptable for use in 2-hour rated walls and ceilings.