For remodel or new construction Applications fits 16 in. to 24 in. ceiling joists, fits all ceiling fans, and installs without going into the attic Includes a heavy duty 15.5 cubic inch dual mount box and mounting hardware Maximum load rating for ceiling fans: 70 pounds, fixtures 100 pounds Support fan brace has locking screws and teeth Each end screws into joist independently, with 4 teeth and single screw on each end 8-32 threads for lightweight fixtures, 10-24 threads for ceiling fans 15.5 cubic in. capacity