Ceiling mount box for ceiling fans, smoke & carbon monoxide detectors, and light fixtures. UL (Underwriter's Laboratories) listed for 50-pound paddle fan support and 75-pound light fixture support. Side beam mounted with (3) 2-inch #10 hex head screws. Ideal for upgrading light fixtures to light paddle fan combos. Versatile and ideal for old work and retrofit applications. Heavy-duty design for support of moving loads. Extra deep for paddle fan components. Nylon locking nuts for secure paddle fan attachment.