Enjoy Smooth, Precise Cursor Movement Kensington Expert Mouse Trackball with Diamond Eye Optical Technology. Designed for PCS and Mac's, the new Expert Mouse employs Kensington's Diamond Eye Optical technology for smooth, precise cursor movement. Surrounding the ball, Kensington has a brand new implementation of its award winning Scroll Ring that puts scrolling right at your fingertips. More comfortable than ever, the Expert Mouse even comes with a soft new wrist rest-right in...