Built in Li-ion battery, rechargeabe via USB cable.     
Micro 5Pin                                                                          
LED for bluetooth connection
1) Product instruction ﹕The product is for 2.4GHz wirless keyboard & mouse set
2) Electrical specification ﹕
1, RF specification
  A. Working  frequency: 2.400GHz-2.483GHz
  B. Auto hopping  function
  C. Working distance: >10m
2, Receiver
  A. Interface type: USB3.0
  B. Working voltage: 5V±5%
  C. Working current: <100mA
3, Keyboard
A. Built in Li-ion battery :180mAh
B. Working voltage:1.8V-3.3V
C. Working current: <2mA @ 3V
D. Sleeping current: <50uA @ 3V
 E. Sleeping mode: The keyboard automatically enter sleep mode when you are not using in 10 minutes.
F. Sleeping waking way: To press any key
G﹕ KEY volume: 78Key,the mainly material : ABS