This device lets you stream music and calls directly from your Bluetooth device to your car FM stereo system. The built-in microphone provides you with an amazing hands free function. It also features a USB and TF card slot that lets you stream your favorite MP3 tunes to your car's stereo system. Play music files from external device by connecting your music device using the Aux-in port too. It also can charge your phone using the DUAL USB charging Port. Its Bluetooth chip can be used with a wide range of device.Feature1. Wirelessly transmit phone call from bluetooth mobile phone to the car FM stereo system.2. Dual USB port charge other devices, multiple electronic devices at the same time meet the charge, like Apple iPhone, iPod, iPad, Android, Samsung and other smart phones.3.