Now there's a mouse that works so well, you are free to focus on what you are doing, instead of on your mouse. The Logitech Wheel Mouse records motion optically, instead of with a ball so there?s no ball to break or get dirty even in the dirtiest work spaces. And no ball allows Wheel Mouse glides smoothly across most surfaces so no mouse pad required. This revolutionary mouse shape nestles into your left or right hand. Save time by using the buttons for shortcuts. Enjoy easy scrolling without scrollbars. Click the Scroll Wheel and the Logitech WebWheelTM feature puts browsing commands and web sites at your fingertips. 5-year warranty