Instruct: Classify Amazon reviews into positive or negative sentiment
Query: Logitech Trackman

Great product! I hate having to drag a mouse over a mouse-pad. This product allows me to leave the mouse stationary and just move the ball. It is much easier on the wrist if you use the computer as much as I do. This mouse and an erganomic keyboard could do much to eliminate carpal tunnel syndrome in PC users. Add to that the customizable buttons and it is everything you could want in a user interface!