Bluetooth FM Transmitter with Hands-free Car Kit Charger, which support USB driver and TF card. It can automatically play and transmit the MP3 files of USB driver or TF cardExcellent HI-FI Stereo Sound Quality: Bluetooth sound processing A2DP, High-performance built-in microphone with Echo cancellation and noise suppression (CVC) technology which can offer your clear talking and wonderful musicHandsfree Calling: Simply paired your phone with the Bluetooth Adapter and its hands-free system can set free your hands during answer the calls and let you safely driveQuick and safe charger: 5V/2.5A USB charger will automatically adjust the output power to different smart phone. Used for mobile phone quick charger without damage your battery.Easy to use：pairing your phone and FM transmitter by bluetooth, insert device in the socket, switch to FM radio mode, make sure FM transmitter frequency the same as car's FM, then you can enjoy your music what you want !