20 CUIN Capacity, Ceiling Fan Outlet Box, 4"Dimater x 2-1/4" Depth, 6 Integral Clamps, Mounts Directly To Existing Ceiling Joist, Rated For Fan Weight Up To 35 LB, Rated For Fixture Weight Up To 50 LV, PVC Construction, Non-Conductive, Non-Corrosive, Lightweight, Easy To Install, Carlon Electrical Box.