First-time use1.Plug the transmitter into the cigarette lighter socket. The product will start up and LCD will display the car battery voltage.2.Open the car audio system and select an vacant FM radio station.3.Tune the FM frequency of transmitter same with the car radio.4.Search the transmitter"T43"via phone bluetooth,there is a voice prompt after paring successfully. Features 1. bluetooth answer, hang up, reject, redial phone and other functions2. Support bluetooth stereo music playback3. Support dot matrix display4. Support Car Accumulator voltage detection5. Support TF card to play music(1G-32G)6. Support MP3/WMA/APE/FLAC/WAV format7. Support FM full frequency 87.5-108.0MHZ8. Auto power-off memory function9. USB 1:5V/1A Charging10. USB 2: 5V/2.4A charging recognition11. Support voice prompt of mobile navigation12. Aux in/out13. Support Caller ID display14. Support the activation of mobile phone voice assistant