PREVENTS WRIST DISCOMFORT - Evoluent's ergonomic VMDMW 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 Medium (VMDMW) and Large (VMDLW). 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. CONNECTION: Wireless USB Receiver 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. HARDWARE COMPATIBILITY: VerticalMouse is plug-n-play compatible with all operating systems that support USB. Basic button and wheel functions work without additional drivers. SOFTWARE COMPATIBILITY: VerticalMouse comes with Mouse Manager software for customizing the buttons. Mouse Manager is compatible with: Windows 7 and 10 Mac OS 10.5 to 10.14 (update for 10.15 is under development. Third party software may be used in place of Mouse Manager for OS 10.15.)