Feature: The product is made of high quality aluminum alloy and ABS material, which is beautiful and hand feels is good. Support for multiple devices or systems, for windows, Android. In addition to being used as a numeric keypad, it can also be used as a HUB. The two expansion interfaces are USB3.0, which transmits 5Gbps per second and is compatible with a variety of devices. 34-key design, a good helper for number input processing. Support theoretically the maximum transmission distance of 10 meters, more convenient and flexible to use. Type-c to type-c public data line USB3.1Gen2 does not recognize the direction of anti-intrusion, omni-directional accessibility to quickly read data. Specification: Model: BT181Pro Color: Black; Silver(Optional) Material: aluminum alloy + ABS Support system: for Windows , OS, Android Number of keys: 34 keys HUB interface: 2*USB3.0 USB transfer speed : 5Gbps Keyboard life (keystrokes): 5 million times Button response speed : 5 milliseconds Wireless / BT transmission distance: 10 meters Working voltage and current: 3.7V/2mA Built-in lithium battery: yes Battery type: polymer lithium battery 302323 (110mAh) Charging time: 2 hours Use time: 50 hours Size: 14.7 * 11.5 * 1.3cm / 5.8 * 4.5 * 0.5in Package list: 1 * Keyboard 1 * Type-c cable 1 * User manual Note: The actual product color may deviate from the photo due to light. There may be a slight deviation in the measurement of product. .