Ergonomic Design & Large Size - The real ergonomic shape fits your hand very well, designed with thumb and pinky finger rest, which keeps your wrist/arm being in nature position and alleviates the strain/pain on your wrist It fits better for Large/Men hands, maybe NOT very comfortable for Women/Small hands (Right-handed)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 Rechargeable & Wireless - Built-in rechargeable Li-battery This ergonomic mouse lasts about 12-20 days under moderate use after fully charged The backlight can be separately controlled It works while charging 2 4G wireless connection, no wire hassle 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, Mac, Linux (NOTE: The side forward/backward button is not recognized on Mac) SpecificationsBattery Capacity: 400mACharging Time: about 2 hoursDPI: 800-1200-1600Key Life: 5-million timesCompatibility: Windows, Linux, Mac(The forward/backward button is not recognized on Mac)Colour:BlackMaterial:ABSSize:12 3x8 9x7 2cmPackage Contents:1* wireless mouse1* USB charging cable1* English manualOnly the above package content, other products are not included Note: Light shooting 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