Wirelessly transmit audio to the car FM stereo system via Bluetooth and switch to hands-free mode when receiving a call. The wired microphone allows you to attach it via the hook and loop tape near your steering wheel for better voice quality and features a talk button. Includes 2 USB ports to charge your smart devices and a voltmeter to display the state of your car battery on start-up. The unit plugs straight into an available 12V or 24V cigarette lighter socket and includes a 0.9" LED screen. A Quick Charge 3.0 ultra-fast charging port keeps your smartphone ready for action as well as a standard 1A USB charging port. Google Assistant Siri Support through Bluetooth. Wired Microphone with Talk Button Hands-Free Calls Quick Charge QC3.0 1A Charging Ports USB Flash Drive Playback Start Up LED Voltage Display MP3, WMA, WAV, FLAC 3A Max (QC3.0 Charging Port) 1A Max (Music/Charging Port) 4A Total Length 80mm Diameter 34mm Weight 40g