Generic 2.4G Wireless Ergonomic Vertical Optical USB Mouse Mice 800/1200/1600DPI 5 Buttons Wrist Healing for Laptop PC Computer Gray Scientific ergonomic design encourages healthy neutral "handshake" wrist and arm positions for smoother movement and less overall strain. 800 / 1200 / 1600DPI resolution optical tracking technology provides more sensitivity than standard optical mice for smooth and precise tracking on a wide range of surfaces. Vertical ergonomic design perfectly fits the natural contour of the wrist and the palm. Professionally designed for office staff and gamers. The right, left and roller key are uniquely deigned on the side, which can place the hand under the most relaxed state during using thus reduce the fatigue of the hand. Easy to use buttons: All buttons are easily operable without contorting your fingers. The button force is light for easy clicking, but still firm enough to avoid accidental actuation.