Description: 2.4ghz wireless transmission effective distance up to 8-10 meters. AVAGO 5090 photoelectric chip is linear stable and has strong surface crossing ability. The current is 14mA, and one No. 7 battery can be used for 1-3 months. It has the function of automatic no signal power off, which is more power-saving. Handwritten input, can be used on a narrow desktop. Handwritten design, comfortable to use when sitting at different angles, not tired. Humanized key position design, grasp very convenient. Mouse small base, place does not take up space. Specification: Material:ABS Plastic Number of keys: 4 Wireless carrier frequency: 2402mhz-2480mhz Wireless working channels: 16, automatic frequency hopping Rated working voltage: 3V Rated working current: 15 mA Tracing system: optics Speed: 14 inches per second 3 CPI adjustment: 800/1200/1600 Support system Windows 7/ Vista/ XP/ 2000, Android, Linux, Mac OS Size Chart: Size:Approx. 140x20x15mm/5.5x0.8x0.6inch Package Includes: 1 Piece wireless mouse pen 1 Piece USB Note: All dimensions are measured by hand, there may be small deviations. Color may vary slightly due to the color setting of each individual monitor. Thanks for your understanding. Please enjoy your happy shopping time!