Kensington Trackball Mouse - Wired Ergonomic Orbit, For PC, Mac and Windows with Scroll ring, Ambidextrous design and Optical tracking ideal for Home Office - White (K72500WW),40 mm Ball : Amazon.co.uk: Computers
Kensington Orbit Optical Trackball Silver/Grey 64327EU | Printer Base
Optical Trackball Mouse - Kensington - Adapt-IT
Kensington Orbit Mouse - Wireless Mobile & Compact Ergonomic TrackBall Mouse for PC, Mac and Windows with Touch Scrolling, Ambidextrous Design and Optical Tracking - Red (K72352EU) : Amazon.co.uk: Computers & Accessories