Ergonomic Design: A well-designed and contoured mouse body supports your palm and cradles your thumb and finger. The ergonomic design allows smoother movement and prevents wrist strain caused by traditional mice High Responsiveness: Simply press the DPI button and switch between DPI levels 800, 1200 and 1600 to adjust the mouse's responsiveness to suit whatever you're doing. Optical Tracking Technology ensures greater sensitivity for precise tracking on a wide range of surfaces Usb Charging Built with High capacity battery , you can easily charge the vertical mouse with the micro USB cable anywhere, no bother of replacing the batteries. When battery power is low, the power red indicator light will flash; while charging, the power indicator light turns blue and it will turn off after fully charged. Stable Wireless Transmission Technology: 2.4GHz wireless technology can provide a reliable connection and not be subject to any interference in the 360 degrees within 10 meters. Enjoy the fast data transmission at the convenience of the wireless technology Wide Compatibility: Compatible with most system including Windows 2000 / ME / XP / Vista / 7 / 8 / 10 / Mac /Linux etc?Not fully compatible with Mac OS system, forward/backward side button not function on Mac? Specifications: Size:4.1*2.7*2.3 inches Weight:140 g Material: plastic Engine: Optical Resolution: 800-1200-1600DPI System supported: Windows series/Mac/Linux Power supply: Built-in 3.7 V 500mA lithium battery What You Get 1 x Wireless Ergonomic Mouse 1 x USB charging Cable 1 x USB Receiver ?The usb receiver for the mouse is in a small transparent bag inside the box, thanks! !?