"The Kensington Orbit Optical Trackball offers precision clicking at the touch of a finger, even on desks where space is at a premium. The ambidextrous design and simple two-button interface make it easy for anyone to discover the benefits of a trackball. The compact footprint is perfect for cramped desks where a mouse is difficult to use. Free Kensington TrackballWorks software lets you customise the buttons and pointer speed to personalise your work environment."