The Logitech TrackMan Marble gives you superior comfort - for either hand. Ambidextrous design provides long-lasting comfort for right- and left-handed people. Convenient button controls let you easily move forward and backward when you're surfing the Web. Click the large buttons together and use the ball for auto-scrolling. Fingertip-based control enables fast, accurate cursor movements. Patented Marble optical technology ensures smooth tracking. Left handed? Right handed? When you're working on your computer day and night, and you want more flexibility, the Logitech Trackman Marble will help increase your comfort level.