The KSI-2105 Charcoal Mini Desk Keyboard with laptop style keys and built in trackball. Keyboard comes with your choice of a PS/2 or USB receiver unit. It offers full 104 key functionality. Smooth, effortless cursor movement with self cleaning trackball. The Infrared transmission protocol broadcasts up to 9 meters in a 45º conical projection giving broad receiver coverage from anywhere in the room. 