PREVENTS WRIST DISCOMFORT - Evoluent’s ergonomic VMDL gently supports your right hand in an upright neutral position The patented shape prevents you from twisting your forearm like what you usually do with an ordinary mouse. ALSO AVAILABLE in Small (VMDS) and Medium (VMDM). The Size Chart for hand size has been updated as of 1/8/21 PROGRAM YOUR MOUSE TO YOUR NEEDS - Install the Evoluent Mouse Manager onto your computer to configure the VerticalMouse’s buttons. Not only can you change their function but you can also set how the buttons work within different programs. GROOVED BUTTONS - Your fingertips rest in a shallow groove on the buttons. This patented innovation secures the mouse in your hands and makes moving it much more precise. ADJUST MOUSE-SPEED FROM LOW TO HIGH - You can adjust the pointer speed from low to high with the optical sensor controls on the side of the mouse. There is no need to release the grip for speed adjustment.