This autochanger allows you to add a 10 disc changer to your existing car stereo without having to match names and models of stereos. It works by plugging into your aerial, and tuning into a specific frequency(88.3 FM). On this frequency, you listen to the changer, and it comes with a little control panel that sits on the dash to operate it. It is a really good idea, as it means that if you bought a head unit that doesn't have disc changer capabilities, you can use this product as an alternative to buying a new disc changer package(expensive!) Apparently the signal fades slightly if you go under through tunnels, as it is a radio frequency that it tunes into, but apart from that, it is a very good product that cuts the cost of getting a disc changer in your car.