Features: 1) Able to change the audio signal into frequency modulation signal and transmit wirelessly to the sound box of the car and play 2) No need to change any original equipment and is convenient and economic 3) Fashionable, smart, stereo voice and convenient operation 4) Frequency: FM 107.7±0.5MHz, changeable 5) Multi-function enables you to have your own FM channel without changing the MP3 or CD of your car 6) Adopts the latest 3D technology and make the tone the same as laser, CD and television 7) Adopts phase-lock loop technology, which ensures stable frequency radiation while functioning at a distance of up to 30m without dead areas so that you can still enjoy Hi-Fi music at home or in car 8) USB charger function that can supply the power for your MP3 while you\'\'re enjoying the music in your car