Product detailsWireless transmit phone call from Bluetooth mobile phone to the car FM stereo system.Built-in FM transmitter, full frequency: 87.5-108.0MHZ.With built-in microphone and automatically calling-number systemSupports USB disk and SD cardSwitch to Hands-free mode automatically from music playing status when receiving callsDual USB charging port for charging iPod/ iPhone, iPad and other mobile device.