Receptacle only, side wired. 250W-250V. Ceiling receptacle lampholders mount on 4" outlet boxes and have breakouts for 31/4" box mounting. Mounting screws included. Porcelain parts are finest high strength insulator porcelain, completely vitrified with brilliant white glaze. Socket interiors are removable and feature a dust ring to protect against plaster and dirt. Pull cord versions include a length of ball chain, connector, 3' of cord and end bell. Shade holder grooves.