FM Transmitter FunctionOur FM Bluetooth Transmitter Car uses Bluetooth 4.2 technology and is compatible with iPhone, iPad, iPod, tablet and Android smartphone. 3 Playing ModesA: Play music from Bluetooth-enabled devices via FM signal; B: transmit music from USB flash disk (up to 64GB); C : stream music from your MP3 player,tablet etc to the car stereo system via 3.5mm audio cable. Dual USB PortsThis USB Car Charger Car Kit with dual USB ports.The 5V/3.1A USB charging port can get your devices like smart phones and iPads full charged in short time, and the other one with USB icon is designed for reading USB files. Easy to Use Car Battery Voltage Display and Automatic Connection.When the bluetooth transmitter car aux is inserted into the car cigarette lighter, the car voltage is displayed.Memory function makes auto-connect to the last paired phone possible. High Stereo SoundEasily make crystal clear hands-free calls with CVC noise cancellation technology. Easily answer/end/reject calls/recall the last number/adjust the volume through the multi-function button, while listening to your own mobile music and audio GPS navigation, the latest noise reduction technology guarantees the quality of the call and playback sound quality comparable to CD playback. In addition, the compact design saves space and prevents the gear lever from drive.