Wireless Ring Mouse : Mini Mouse optical sensor 800 dpi that clings to the index. Mouse uses wireless radio waves. Compatible WinME/2000/XP/Vista , Mac OS X 10.2 and higher, and Linux (also suitable for Ultra Mobile). USB 2.0 connection. Insert the ring, attached to the mouse, onto your finger. Plug the USB dongle on your computer, and immediately use your Wireless Ring Mouse. The left square with the small red ball (scroller) is used to move the mouse around the screen. The two bottom squares are the equivalent of "Right Click" and "Left click" on a classic mouse, and the square at the top right will allow you to, by pressing once, scroll!