You need
In-Car CD/MD/MP3 Adaptor
Shark
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A simple-to-use adaptor that is built into a standard audio cassette and requires no power. Simply plug the lead into the headphone socket of your personal CD, MiniDisc or MP3 player and pop the cassette into your car’s cassette player and press play. You will now be able to listen to the music through your car’s speakers. Also in the kit is a 9Vdc-12Vdc power supply that plugs into your lighter socket and powers your CD/MD/MP3 player.
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