The patented shape of the Evoluent Verticle Mouse supports your hand in a relaxed handshake position that eliminates forearm twisting, with new Larger flange for your pinky to relax. The grip is the same as an ordinary mouse, just turned sideways, and the buttons are operated by the same fingers. The position helps to aleviate wrist pain and other discomforts that come with using a traditional mouse. Comes in both a left-handed and right-handed model. A small right-handed size is available for hand lengths smaller than 7 inches (See chart).