The device transmits waves to the car radio, which plays sound from a microSD card, flash drive, or directly from the phone via Bluetooth. Additionally, it functions as a hands-free kit thanks to the built-in microphone. Technical Specification: color display 1.77 inches power supply: 12/24V cigarette lighter socket Bluetooth 4.2 + EDR Distance from microphone: 0.5-2m Bluetooth range: 10m microSD card slot (up to 32GB) voltmeter - battery charge meter LED backlighting track name display USB port for device charging with Quick Charge 3 standard.0 USB port for playing music from a flash drive (up to 32GB) / charging 5V 1A dedicated buttons for handling phone calls File format: MP3 / WAV FM frequency: 87.5 – 108.0 MHz input AUX minijack 3.5mm flexible arm - allows convenient use of the device in any car minijack-minijack cable 3.5mm approx.1m in the set