... play intelligent connection When USB NANO transmitter connect to the USB port of PC/ Laptop , NANO USB transmitter direct decoding ,no need ... efficient charging of lithium battery, Dual charging mode of USB and Li-ion can be permanent power life , ... size: Φ2cmReception range and distance : 10M, 360 °Interface: USB 2.0 Package Contents :Wireless headset, USB transmitter,Charging cable, User’s guide