brand new and high quality Features: A genuine Ergonomic mouse with vertical design, adding more comfort to the wrist. Arched mouse back with arc ring design, can perfectly fit the natural state of the for palm. Professionally designed for office staff and gamers. The right, left and roller for key are uniquely deigned on the side, which can place the hand under the most relaxed state during using thus reduce the fatigue of the hand. The right side of the mouse is equipped with the function of forward or back to turn pages, which makes your work more convenient and flexible. Built-in iron, making center of gravity more stable. Built-in rechargeable lithium battery, more convenient and practical for use. Connection method: Wireless Resolution: 1600DPI Connection port: USB 2.0 Operating voltage: 3V Operating Current: 13mA Key: Left/right for key, roller for key, forward/back for key, on-off for key Wireless range: about 10m Battery: Built-in rechargeable lithium battery Working time: about 20 days Support system: Win98/2000/XP/VISTA/7/for MAC Size: 105*71 *78MM/4.13*2.80*3.07"(L*for W*H) Color: Black Quantity : 1 Set Note: 1 USB cable can only be used for charging. It can not be used as wired mouse. 2 It can be used while charging, but you must make sure premise that plugin the USB receiver in the computer and opening the power of mouse. Note: After receiving this product, please charge for 1-2 hours before use it; This product comes with automatic electricity saving function, while using; If the receiver is not connected to computer, the light of the mouse will be automatically off, and the receiver is connected to computer, then can be in normal use.