It stays, firmly planted in place. Period, it's that simple. Plus, it features a positive/negative wheel for up to 10 degrees positive to 20 degrees negative tilt. It also has a right or left mouse pad mounting and gel palm rest for comfort. Lightweight aerodynamic design fits most office keyboards. Size: Overall length with mouse platform is 22 1/4" minimum to 28 1/4" maximum. Keyboard tray adjusts 5 1/4" to 8 3/4" maximum depth. Mouse platform diameter is 9 13/16". Gel palm rest is 2 1/4" deep.