1. Streamlined design for comfortable grip. 2. Built-in with 280mAh battery, rechargeable and has long use time. 3. 800/1200/1600DPI for selection 4. ABS frosted texture, anti-sweat and anti-skid. 5. Specification: Size: 11.3x5.75x2.6cm Switch afford: 60+/-10gf Connection distance: 8~10m Protocol: OTS Wheel direction: two way Switch life: 3 million taps Connection mode: wireless Working current: less than 70mAH Working voltage: DC 4.75V~5.25V Battery capacity: 280mAh