Dual USB LCD AUX-IN Audio Car Kit MP3 Player FM Transmitter Charger For iPhone iPod Samsung Nexus HTC Smartphones Built-in FM transmitter. Support USB disk and Micro SD card. With 3.5mm line-in jack, support external audio devices. Dual USB charging ports for charging iPod/iPhone, Samsung, iPad, Nokia and other mobile devices (Output 5V/2.1A). Support 12-24V voltage from the car cigarette lighter.