Contoured, natural (46. 7 Degree) slope keeps the wrist in a neutral handshake position, eliminating soft tissue compression. Fully-featured mouse with scroll wheel, left, right, forward, back, and DPI (800/1000/1200/1600) buttons. Simply plug in the Nano receiver for plug & play wireless connectivity up to 20 meters (65. 61 feet). A low battery indicator let's you know when it's time to change the battery, so you're never caught off guard. One AA battery lasts up to a year. Nano receiver conveniently stores inside mouse when not in use. Free downloadable KensingtonWorks software provides button customization