3M Vertical Mouse Vertical Mouse encourages a natural vertical hand position with the thumb pointing upwards. A Traditional mouse design means you have to twist your forearm to put the palm of your hand in a horizontal position over the mouse. Because of this and the repetitive use of the index finger for clicking, the traditional mouse can contribute to Repetitive Stress Injury and Carpal Tunnel Syndrome. The 3M Ergonomic Mouse has been clinically proven to relieve pressure from the "Median Nerve" in the wrist when mousing. This has been shown to reduce muscle load and the incidence of discomfort associated with disorders such as Carpal Tunnel Syndrome and Repetitive Stress Injury. It has the following features: MAC& PC Compatible USB & PS/2