This product is Bluetooth hands-free phones, Bluetooth FM transmitter automotive car charger car MP3 card recognition of comprehensive function. S7 is a special kind of Bluetooth FM transmitter, Bluetooth hands-free car, car mp3. He USES professional high-performance Bluetooth module, the built-in MP3 / WMA decoding chip, can U disk or TF card wireless transmission to the car stereo music files. And, as long as your mobile phone with Bluetooth, can you phone to your car stereo music launch, calls can switch to the h-f state, at the end of the conversation, will automatically switch to the music played. Its built-in FM launches, MP3 decoding, and stereo Bluetooth wireless transmission chip, to be able to TF card, U disk, mobile phone audio or songs played back through your car stereo, do not need to be modified your car, can let you drive on the way can enjoy the music and you can use a hands-free phone calls, entertainment, security.