Style:In-EarConnectors:USBCommunication:WirelessBuilt-in HD and sensitivity microphone. Ideal for in-car calling or working use. Support A2DP 、 makes you can enjoy clear and natural sound when calling.Built-in 50 Mah polymer battery. Up to 4 hours of continuous talk time、 3.5 hours of music time.It can be connected with two smartphone at the same time.The wireless range up to 10 meters on open air. The headser will be connect automatically with a phone paired previously. Due to the difference of people's ear、 this earphone maybe not fits everyone. If the one you get is not perfect for you、 please let us know. We will find a best way to help you. Notes:1.If you can't pair the bluetooth with your phone 、 please make sure this headset has been going into pairing mode. (Turn the bluetooth on and keep press the function key until the LED light flashing Red and Blue) 2. If your phone can't search the bluetooth、 please kindly try to restart your phone. 3.This bluetooth can work for most bluetooth device. If you can't pair it、 please feel free to contact us. We will try our best to help you. 4.The size of this bluetooth is derived from the test date of our engineers. It can be suitable most person's ear. Please kindly understand it could be not suitable for you completely. We will be much appreciate if you would like to contact us when you find the earphone is not fit for you Package Include:1*headphone1*instruction1*USB charging cable