3.0 bluetooth receiver，Audio conversion.Extenal memory， with remote control and host.Function:1.Bluetooth hands-free Car FM transmitter2.Wireless transmission of telephone，Bluetooth mobile phone to the Car FM stereo sound system3.Support A2DP bluetooth4.Switch to automatic mode from the hands-free， playing music， when the call arrival5.Support the U disk and the Micro SD card6.Support MP3/ and WMA format file