The Optical Wheel Mouse from Logitech offers you the latest optical sensor technology. Due to the 400 dpi sensor working on almost any surface is possible giving you the accuracy you need to position the mouse pointer in a short time to any point of the screen. The Optical Wheel Mouse supports both interfaces: PS/2 and USB. The enclosed PS/2 adapter helps to use the Optical Wheel Mouse either on USB or PS/2 interface.