[NOTE: The USB receiver at the bottom of mouse.]The unique, upright and ergonomically superior design of the Vertical Wireless Mouse reduces harmful arm and wrist tension by allowing your hand to operate the mouse while remaining in its natural position.You deserve itAdvanced "Page Back" and "Page Forward" functionality buttons provide convenience when web page browsing. 800 /1200/1600 DPI Levels -- Easily adjusts the sensitivity of the mouse.Built-in rechargeable battery. You no longer need to buy batteries, very convenientEASY TO USE -- One nano USB receiver at the bottom of mouse.2.4 GHz wireless technology which provides a powerful, reliable connection up to 10m. PLUG & PLAY, without installing any additional software. Enjoy the fast data transmissiot the convenience of the wireless technologyWidely compatible with Windows 2000 / XP / Vista / 7 / 8 / 10 / Linux. Once you get used to the ergonomic mouse, you will love it so much