The Tilt-A-Wheel Cobra™ Sit & Stand Adjustable Keyboard Arm may be placed in seated or standing height. Just lift, adjust and release to lock the tray in place with 12 ½" height adjustment ranging from 7 1/2" above the track to 5" below. The Soft Touch Wheel controls a 10 degree positive and 20 degree negative tilt for maximum wrist comfort, 23" glide track as a slim profile for maximum knee clearance under mechanism. Exceeds ANSI/BIFMA standards All steel construction with black powder coat finish