This is a transmitter with the function of playing music and receiving calls from your smartphone. One of its main advantages is two USB ports for fast charging with PD and QC 3.0 technologies. You can charge two devices at the same time, and it charges up to 4 times faster than a regular outlet. There's also a dynamic bass boost function to enhance the sound of music in your car speakers. The blue backlight pulsates to the rhythm of the music. Compatible with all Bluetooth-enabled devices and any 12-24V vehicle.