Kensington Orbit Wired Optical Trackball Mouse Black/Silver 64327EU DDIf youre looking for a simple way to transition from a mouse to a trackball, look no further than the Orbit Optical Trackball designed for both Windows and Mac. It offers better ergonomics, with less wrist and hand movement that will ease the pain of repetitive stress injuries. Optical tracking technology delivers precise cursor control at the touch of a finger while the ambidextrous, two button design provides a familiar user experience for mouse