The device transmits waves to the car radio, which plays sound from a connected external USB source or microSD card. Additionally, it functions as a hands-free set thanks to the built-in microphone and Bluetooth technology. The transmitter has a readable LCD display that shows the titles of the tracks being played. Technical Specification: Power supply: 12V/24V cigarette lighter socket Bluetooth 5.0 + EDR built-in microphone for phone calls Microphone distance: 0.5-2 m 1 USB charging port 2.1A 1 port USB for connecting a storage device Bluetooth range: 10 m AUX input miniJack 3.5mm built-in voltmeter TF & USB: up to 128 GB File format: Mp3 / WMA FM frequency: 87.5 – 108.0 MHz SNR: >60dB menu in Czech language The package includes a minijack-minijack 3.5mm cable and a spare fuse.