The solar mobile charger is not only a Solar Charger but also a MP3 Player with FM transmitter. The device converts the sun light power into electrical power. It is working as: the solar panel transfer the sun energy into electrical energy which is stored in the built in rechargeable Lithium battery, the stored power is then exported to mobile phone, MP3, MP4 and other digital products, of which the process is done by the control circuit, and the different adaptable connector. It contains a built-in MP3 player with FM transmitter, you can enjoy your favor music via earplug and transmit music through the FM transmitter as a car mp3 player.