Kensington Pro Fit Ergo Vertical Wireless Mouse Black K75501EUThe Kensington Pro Fit Ergo Vertical Wireless Mouse with its natural handshake position, improves wrist posture for better comfort. In an independent study conducted by professional ergonomists, users rated the vertical mouse as the most comfortable and that it conformed to their hand naturally. Extended lip for little finger provides complete support for smoother, larger muscle group movement Number of Buttons: 6 With scroll wheel, left, right,