The EW3157 Wired Ergonomic Mouse is a good solution when spending much time on a computer. Many common symptoms of hand/mouse related strain are prevented and reduced by using this ergonomic mouse. Work more comfortably thanks to the ergonomic design. Your hand, wrist and forearm are supported more naturally. The EW3157 Wireless Ergonomic Mouse is equipped with five buttons and a scroll wheel. It has a high precision 1800 DPI optical sensor and a DPI button to switch between the four DPI levels: 600-800-1200-1800. The mouse is USB powered via the 1.25m long USB cable.