I have several for sale. Some mount to the back of the desktop and some go through a grommet hole in the desk. Allows monitor to be positioned at the correct viewing distance and promote stress-free movement Tilt mechanism operates through a range of 20º backward tilt and 30 º forward tilt Rotation allows for landscape or portrait viewing of monitor Built-in counter-balance tool for easy balance of the monitor Comes with 75mm/100mm VESA compliant mounting plate These are business grade arms and retail for $300 new.