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 the box! You get all of these great new features along with the same, large ball, exceptional control, and ease-of-use that has set the industry standard for more than 15 years.