Lenovo 31P8700 USB+PS/2 Optical 800DPI Black mice

31P8700 ThinkPlus ScrollPoint Pro Optical Mouse USB & PS2 (Business Black) Bring more accurate maneuvering and control to your desktop with the Optical 3-Button ScrollPoint Mouse PS/2 & USB 800 dpi sensor. The 800dpi optical sensor is more accurate and faster than before. The ScrollPoint pointing stick is ideal for both horizontal and vertical scrolling, unlike standard wheel mice. Optical technology provides precision control and has no mechanical ball, thus there is no need for a mouse pad.