1、Compatible with Bluetooth 0 20730 chip, 1 to 1 wireless connection, no interference. 2、Support for Windows, for Android, for Mac OS systems. 3、Built-in 350mAh large capacity soft pack polymer rechargeable battery, can charge the keyboard through Micro USB charging interface. 4、Multi-function 28-key numeric keypad for increased productivity in Excel spreadsheets, accounting tasks and financial applications. 5、Ergonomically dip angle design, with non-slip mats for a better experience. 6、X-archaic keycap design, comfortable button feel. 1 x Numeric Keypad 1 x User Manual 1 x USB Cable Item Type: Numeric KeypadOptional Color: Black, GrayCompatible with Bluetooth Solution: 20730 chip compatible with Bluetooth moduleCompatible with Bluetooth Protocol: Compatible with Bluetooth  3.0Working Distance: About 8 Meters in Barrier-Free ConditionsOperating Voltage: DC 3.7 VBattery Capacity: 350mAhWorking Current: <5mAContinuous Working Time: 70H (350mAh Battery Calculation)Standby Time: 90 DaysSleep Current: < 70uACharging Current: <150mACharging Voltage: DC 4.7~ 5.2vSleep State: The keyboard enters sleep after 20 minutes without action;Status display LED: 1. LED is blue light 2. Power on and the blue light is on, and after 1S, the blue light flashes slowly 1 time and goes out; 3. Press and hold the code button for 3 seconds and the blue light flashes into the code status. The devices do not need to input the password, just select the devices connection 4. Low voltage indication: In the blue light is working state, the flashing is low voltage indication