CLAMP ON FOR MORE SPACE AND COMFORT! Position your monitor for space-saving, comfortable viewing. Arm extends up to 20.5" in any direction. Tilts up to 90 degress in all directions. Three height levels. Easily assembled and attached. Sleek design fits desks up to 4" thick. Accommodates "VESA compliant" or "zero footprint" flat panels up to 20lbs.