Dual USB Port & Safe Charging- It has two USB charging ports, one supports 1A charging and one supports 2.4A charging. It can charge two devices at the same time and has overcharge protection. The device is safer when charging Hands-free Calling- Bluetooth 5.0 transmission technology allows fast connection and stable signal. Automatically connect memorized paired when power on. Rotate function button allows you to easily select FM channels and Play/Pause/Answer/Hang up phone calls Unique LED Design- This FM transmitter designed with blue LED lights, you can see the button clear in the darkness. It will automatically switch on and show the battery level of your car. Make it easier to operate and drive safely when driving at night Excellent HI-FI Crystal Clear Stereo Sound- Built-in microphone with CVC noise reduction technology to create full duplex sound quality offer you hands-free talking and navigation voice broadcast. Full FM radio frequency range from 87.5 to 108.0MHz is wider than what ordinary transmitters Widely Compatibility- This upgraded FM transmitter supports play music via Bluetooth, TF card and USB disk and it will automatically detect and play the MP3/WMA/FLAC/WAV/APE format music . Compatible with most devices on the market.