Lenovo wireless mouse N3903 Lenovo Wireless Mouse N3903 offers exceptional comfort and cordless convenience with it's ergonomic design and the Plug-and-Forget Nano-receiver. Feel-good ergonomic design Comfortable ergonomic design, easily handle with either hand. Save energy The integrated on/off button at the bottom of the mouse allows you to conserve batteries (2 AAA batteries included). Plug-and-forget nano-receiver Comes with a tiny receiver that can stay in your computer - plug it in and forget it. Precision optical tracking Get responsive, smooth cursor control with high-definition optical tracking. Easily works on wood, carpet, and other difficult surfaces.