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 Expert Wired Optical Trackball Mouse Black 64325 AC64325
Kensington Orbit Wired Optical Trackball Mouse Black/Silver 64327EU - One to One Office Supplies
Kensington Orbit Mouse - Wired Ergonomic TrackBall Mouse for PC, Mac and Windows with Scroll Ring, Ambidextrous Design and Optical Tracking - Blue (K72337EU): Amazon.co.uk: Computers & Accessories
Kensington Orbit® Optical Trackball Mouse from Posturite