The EW3158 Wireless Ergonomic Mouse with high precision of 1600 DPI 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 EW3158 Wireless Ergonomic Mouse is equipped with five buttons and a scroll wheel. The on/off switch prevents the rechargeable battery from running out. Charge the mouse with the included charging cable. Is the battery empty? Plug in the USB cable and keep using the mouse while it’s wired.