Bluetooth FM Transmitter: It can be paired as a hands-free kit with most of Bluetooth enabled devices, such as iPhone, iPad, Tablet, Samsung and other Andriod Smartphones; play music and answer calls directly from your mobile devices to car stereo system via FM radio signal( 87.5-108.0MHz). Car Charger: Features with 5V-2.4A and 5V-1A charging ports which output 3.4A total, support charging two devices simultaneously. Built-in smart charging IC, will auto detect your devices and charge them at optimal speed. USB Car Charger: Built in Mic, switch to Hands-free mode automatically from music playing status when answering calls; Answer/ hang up the call or play/pause the music all in one button operation. Car FM transmitter: Insert a USB flash driver which contains MP3 files into the right USB port, it will play and transmit the MP3 files automatically, you can use these files conveniently. Bluetooth FM: Insert it into the cigarette lighter socket, turn your car FM radio on, set an empty frequency, then search and match it to this FM transmitter; Pair it with your device via Bluetooth, then there you go!