Use the Chief CMS018 18" Speed-Connect Fixed Extension Column (Black) to lower your projector or flat panel display an additional 18" (45.7cm) from the ceiling. This column also provides flow-through cable management with a cable exit port for a clean installation. Use in combination with any 1.5" NPT ceiling plate or other accessory. It consists of 1.5" NPT column threaded on both ends. Aluminum construction makes installation easy. Weight capacity is 500 lbs.