The Bluetooth MP3 Player FM Transmitter Hands-free Car Kit Charger, which supports USB driver and Micro SD card can automatically play and transmit the MP3 files of USB driver and Micro SD card after matched with your radio by the frequency. Simply paired your phone with the Bluetooth FM Transmitter and its hands-free system can set free your hands during answer the calls and let you safely drive. A built-in microphone which can offer your clear talking and wonderful music This player has the automatic memory function. It will record the song which you were playing last time and play it again when you restart the car. Moreover, It has two USB charging port which is up to 2.1A 5V to charge most electronic devices. With this product, you have no need to worry about your mobile devices is the lack of electric energy while traveling. It is perfectly suitable for car owners.