The Wireless Evoluent Vertical Mouse 4 - Right Hand has a patented new shape that supports your hand in a relaxed handshake position and eliminates arm twisting. Once you experience the superior comfort, you will never go back to ordinary mice. It now includes an extended lip to prevent surface contact with pinky finger. Features Include: * 1200 dpi true optical resolution sensor reduces hand movements compared to other mice that generally have 800 dpi. * 5 buttons - 3 are programmable with 59 selectable functions each with Windows driver and a new thumb position design for increased comfort. Vertical scroll - press a button and drag the mouse to scroll with greater precision and control than the scroll wheel. Auto click - automatically perform a double click by pausing the pointer. Click lock - press and hold a button momentarily to simulate continued pressing without holding down the button. * Compatible with PC, Mac, UNIX and Linux Versions.