Ergonomic mouse, new definition of grip CENSI mouse is based on the most advanced hand shoe mouse ergonomic design,providing an ultimate solution to prevent RSI and Carpal Tunnel Syndrome. By extensive experiments and data analysis, P.H.D Erik Pepper from USF defined a perfect angle of 33 degree that hand and fingers are fully supported at the ideal angle of 33 degrees makes sure fore arm completely relaxed and naturally stretched out of the tension state of the arm bone to control the mouse by the logic as below: Reduces Wrist and Forearm Pronation The concave depression on the thumb rest of the mouse combined with the downward slope at a 33°degree; angle off the horizontal, which is a more natural position for your wrist and forearm. Reduces Wrist Strain due to Excessive Movements With the Ergo-Grip detachable flange, control the mouse with your whole arm instead of wrist or fingers that only need a minor effort to switch while your thumb rests on its support prevents thumb harmful action. Reduces Grip Requirements The slanted semi-fist shape design provides gravitational force on the hand making sure less more hand fatigue from the grip movements and much more precisely mouse tracking. Reduces skin friction between Fingers and Desk Surface The Ergo-Grip design with detachable palm support keeps the underside of the fifth finger and palm off the surface of the desk. Other Features The interchangeable grip between precision grip and ergo grip provide the best experience both working and surfing Freedom wireless mouse provide barrier free way connection via the USB dongle with 2.4Ghz technology both right and left hand Easy to lift: when precision grip be needed, easy to find the way to lift in details . Multiple choose of size for the best fit: Small/Medium/Large Easy to use : Plug and Play, no learning curve. High DPI responsiveness: switch easily DPI levels between 800/1600/2400, Optical Tracking Technology ensures sensitivity for precise tracking.