Ergonomic design:This mouse is design for users to reduces muscle strain and can even undo the damage that years of using a traditional computer mouse causes. Wrist pain, shoulder fatigue, Carpal Tunnel Syndrome and tendonitis can all be alleviated or, in many cases, eliminated with regular use.Adjustable DPI: The adjustable DPI settings allow you to change the sensitivity of the mouses pointer speed (800 / 1200 / 1600 / 2400), allowing you to decrease speed for tasks that require guaranteed precision or increase the speed faster for browsing.Rechargeable: This mouse doesnt need to use AA battery now .it have battery inside the mouseyou just used USB cable chargingDid not need to worried to buy batteries again againWide Compatibility:IBM or compatible computer. Windows2000/ME/XPx64/Vista/7/8, Mac OS Xover V10.4An available USB port