Logitech Optical Marble Mouse (USB/PS2)
Logitech's Optical Marble mouse gives you the familiarity of a mouse with the convenience of trackball navigation. Designed for comfort in either hand, this space-saving, four-button trackball boasts Logitech's innovative optical tracking system to deliver superior precision and smooth motion with virtually no maintenance or cleaning required. You get two ways to scroll: click two small buttons for page up and page down, or click one of two large buttons and use the ball for auto scrolling. The trackball gives you precise fingertip control, and the included WebWheel software enhances your Internet browsing. Two AA batteries (supplied) keep the Marble mouse racing for about three months.