The Lenovo N3903A Wireless Mouse (Metallic) offers exceptional comfort and cordless convenience. Its ergonomic design provides comfort while allowing users the ability to operate with either hand. The integrated on/off button on the bottom of the mouse allows you to conserve batteries (2 AAA batteries included). Simply plug in the tiny USB nano-receiver and forget it. Get responsive, smooth cursor control with high-definition optical tracking. This mouse will easily operate on wood, carpet and other difficult surfaces.