Kensington Expert Mouse - Wired Ergonomic TrackBall Mouse for PC, Mac and Windows with Scroll Ring, Ambidextrous Design and Optical Tracking - Grey (64325)

KensingtonWorks Customization - Free downloadable software provides an even more personalized experience, giving you the ability to assign a wide variety of program functions to each of the 4 buttons, as well as controlling the pointer speed and scrolling speed
DiamondEye Optical Tracking - Movement detection technology provides smooth, precise cursor control so you can get where you want on the screen quickly with less hand movement, improving productivity and efficiency
Scroll Ring and Large Ball - Spin the dial to move up and down web pages or documents with complete ease while the grey ball has been specially designed with an absolute spherical, hard surface for precise tracking and control
Ambidextrous Design - Works equally well for both right-handed and left-handed users to get the most out of their trackball
Detachable Wrist Rest - Soft cushioning cradles the hand and wrist in ergonomic comfort for pain-free productivity during extended periods of activity on th