PREVENTS WRIST DISCOMFORT - Evoluent's ergonomic VM4R VerticalMouse 4 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. 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. 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. OFFERS OPTIMUM COMFORT - The VerticalMouse 4 has a broader lip along the bottom edge that prevents the pinky finger from rubbing the desk. The thumb has been reshaped from earlier version to provide more comfort. WIDE RANGE OF COMPATIBILITY - USB wired, and is compatible with Windows XP, 7, 8 and 10, Mac and Linux Systems.