1. Innovative horizontal and vertical scroll modes, programming the context menus, as you like. 2. Big-button wheel can be used for double clicks and universal scrolling. 3. Easy zoom-in and zoom-out, stimulates and control keys for direct zooming/page changing control, and various zoom factors and lens available on-line. 4. Control software works with windows 95/98/NT/2000, 5. Various colors design available. 6. PS/2 or USB.