Logitech ERGO M575 Wireless Trackball with Smooth Tracking
Hands-on with the new $50 Logitech Ergo M575 Wireless Trackball - CNET
Logitech ERGO M575 The wireless mouse with trackball, easy thumb control, precision reading and smooth reading, ergonomic convenience, Windows/Mac, Bluetooth, USB - Graphite : Amazon.co.uk: Computers & Accessories