Anker Wireless Mouse, Ergonomic USB 2.4G Wireless Vertical Mouse with 3 Adjustable DPI Levels 800/1200 / 1600 and Side Controls, Black Ergonomic Design: Well-designed, contoured shape seamlessly fits and moves with your palm, allowing smoother movement and preventing wrist strain. High Responsiveness: Switch between DPI levels 800, 1200 and 1600 to adjust mouse responsiveness. Optical Tracking Technology ensures greater sensitivity for precise tracking on a wide range of surfaces. Enhanced Functionality: Added next/previous page buttons positioned where the thumb rests increase web browsing convenience. Plug and Play: Enjoy the convenience of a tangle-free, wireless mouse as soon you've inserted the included USB receiver. What You Get: Ergonomic Wireless Vertical Mouse(2 AAA batteries not included), USB receiver, welcome guide, our worry-free 18-month warranty and friendly customer service.