CMS Speed-Connect Adjustable Extension Columns lower projector to desired height. Provides up to 2' range of height adjustment in 1" increments, depending on model (6" to 12' lengths available). Includes set screw for add stability. Consists of 1 1/2" NPT column, threaded on both ends. Use in combination with any Chief 1 1/2" NPT ceiling plate or other accessory. Designed to adjust length without requiring disassembly. Aluminum construction for easier installation – also saves on shipping costs. * NOTE: Bracket adds 6 lbs/2.7 kg and .94"/24 mm depth to installation. Be sure additional weight does not extend wall or ceiling mount weight capacity.