Details HIGHLIGHT [ Aluminum alloy ] - The product is made of high quality aluminum alloy and ABS material; which is beautiful and hand feels is good. [ Compatibility ] - Support for multiple devices or systems; for windows; Android; Mac os. [ USB HUB ] - 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. [ Cooperate distance ] - 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. (only USB Hub version is type-c port) SPECIFICATION - Material - 038S 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 NOTE - Some keys are not function on mac os or ios. Distinguish (3 version - 1. Aluminum+USB Hub 2.Auminum no Hub 3. ABS No Hub) When you make the order.