Comfort and productivity are at your fingertips with the SlimBlade Trackball. Your computing experience gets smoother faster and easier with a ball that can do it all. In addition to the usual productivity gains that come with a trackball with a simple twist of the ball you ll be scrolling up and down pages. It offers better ergonomics with less wrist and hand movement that will ease the pain of repetitive-stress injuries. Kensington Works sofeware also allows you to turn your trackball into the ultimate media controller so you can adjust volume hit play/pause stop and forward/back. The sleek low-profile design provides all-day comfort while advanced laser technology and a large 55mm ball deliver exceptional precision. Features & Benefits: Scroll up and down web pages and documents with a simple twist of the 55mm ball. Sleek low-profile design offers all-day comfort along with beautiful aesthetics. Laser tracking technology delivers superior precision for increased productivity. Free KensingtonWorks software allows you to customize buttons cursor and scrolling speeds. Windows ARM-based computers are currently not supported. Please check back for future updates on compatibility. Wired 150cm USB cable provides reliability and avoids need for batteries. Plug & Play installation. Ambidextrous design for left or right-handed users. Luxurious Ruby red trackball and metallic silver finish PC and Mac compatible Compatible with Windows Vista and Mac OS X. TrackballWorks software downloadable from www.kensington.com This product is designed to comfortably fit users with average to larger sized hands.