The Westinghouse Lighting Sidemount Plus Fan Box allows you to safely install your ceiling fan or lighting fixture without having to access attic space. The box's design provides secure attachment to an existing ceiling joist. It is ideal for installation during new construction or remodeling, and can be installed in finished ceilings. The Sidemount Plus features a heavy-duty, all-metal, 2-1/8-inch-deep, dual-mount electrical box with a 21-1/2-cubic-inch capacity. To install it in a finished ceiling, simply mount the bracket to a joist through a 4-inch hole in the drywall, pull the wire into the box, and remount the box to the bracket. The box is UL listed to support fans and light fixtures up to 70 pounds. It includes 10-24 threads for heavier fans and fixtures and 8-32 threads for cover plates and lightweight lighting fixtures.