Orbit Trackball with Scroll Ring

idea: comfort meets control.
All-day comfort and scrolling come together in the Kensington Orbit Trackball with Scroll Ring. The scroll ring allows you to fly through web pages and documents. And all while delivering comfort and space savings no mouse can match.
Features
All-day comfort from a world leader in trackball innovation.
Scroll ring allows fast, easy scrolling of web pages and documents.
Uses far less desk space than a mouse.
Optical technology for precise tracking - no cleaning required.
Ambidextrous design for left or right handed users.
Click-free scrolling.
Compatible with Windows7, Windows XP, Windows Vista, and Mac OS X.