Product Description With its sleek gray shape and black button eyes, this innovative mouse looks like the real thing. From Logitech, Marble Mouse features an optical, space-saving tracking system that delivers superior precision, smooth motion and resistance to dust and grime. Mouse is easy to use in either hand while reducing hand and wrist movement. Customize your own mouse settings with the click of a button. Comes with easy-to-install MouseWare software for fast Internet access and easy Web scrolling using either Windows or Macintosh applications. System requirements: IBM or compatible requires Windows 95/98/2000/Me/NT 4.0. Macintosh requires operating system 8.6 or higher. CD-ROM drive (for MouseWare software installation), USB or PS/2 port. No.904360-0403. Imported. 2Hx6Wx2-1/2D'. Amazon.com 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.