The u-Jam car adaptor connects your i-Pod to your car's power source, and charges your i-Pod from your car's cigarette lighter. You'll know your car charger is properly connected by its illuminated LED indicator. The unit is also engineered with a replaceable safety fuse to protect from potentially damaging spikes or short circuits. You can use the car charger with the specially designed cassette adapter for high-quality audio through your car stereo.