1. innovative horizontal and vertical scroll modes, programming the context menus, as you like. 2. middle-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. resolution: 600dpi. 6. various colors design available. 7. ps/2 or usb.