Ergonomic Design & Size - The real ergonomic shape fits your hand very well, designed with thumb and finger rest, which keeps your wrist/arm being in nature position and alleviates the strain/pain on your wrist. It fits better for /Men hands, maybe NOT very comfortable for Women/Small hands. (Right-handed)<br> Silent Click - Left and right click is silent (NOTE: other buttons are general), which makes you conveniently work without disturbing others in the evening, or in the library/the coffee house/the office.<br> Rechargeable & Wireless - Built-in rechargeable Li-battery. This ergonomic mouse lasts about 12-20 days under moderate use after fully . The backlight can be separately controlled. It works while charging. 2.4G wireless connection, no wire hassle.<br> 3 DPI Levels & Compatibility - 800/1200/1600 DPI (slow to fast), adjusted via DPI button. Plug and play. Compatible with Windows 8/7/10/Vista/XP/2000, , Linux (NOTE: The side forward/backward button is not recognized on ).<br> Specifications<br> Battery Capacity: 400mA<br> Charging Time: about 2 hours<br> DPI: 800-1200-1600<br> : 5-million times<br> Compatibility: Windows, Linux, (The forward/backward button is not recognized on )<br> Colour:Black<br> Material:ABS<br> Size:12.3x8.9x7.2cm<br> Package Contents:<br> 1* wireless mouse<br> 1* USB charging cable<br> 1* English manual<br> Only the above package content, other products are not included.<br> Note: Light and different displays may cause the color of the item in the picture a little different from the real thing. The measurement allowed error is +/- 1-3cm.