We may call it a mouse, but the Kensington Expert Mouse® is so much more. It employs our DiamondEye optical technology for smooth and precise cursor control. Surrounding the ball, is an award Scroll Ring that puts scrolling right at your fingertips letting you fly through web pages and documents. There's even a soft wrist rest included with the Expert Mouse® trackball for comfort and convenience no mouse can match. Designed for PCs and Macs and a large ball for exceptional control the Expert Mouse Optical Trackball sets the industry standard.