This cassette adaptor is the easiest most convenient way to listen to any portable audio player through your car&s stereo Plug the audio jack into the headphone port of your iPhone iPod MP3 player CD player or other portable audio device Insert the cassette adapter into your cassette player & start jammin& to your tunes in the car! Listen to music from your MP3 player iPhone iPod or Smartphone through your car&s cassette player Simply connect the 35mm jack on the cassette adapter to your device Works with any audio device which has a standard 35mm jack