Lenovo ThinkPad USB Wired Laser Mouse (MOC9ULA): For accurate control, the ThinkPad USB Laser Mouse (57Y4635) makes use of optical tracking technology. Features consist of: A built-in scrolling mechanism for the wheel No mousepad is needed, and it works on a variety of surfaces. The full-size form is comfortable to hold in either hand. Additionally, the scroll wheel can be used as a third mouse button.