The FM transmitter is a multifunctional device. The applied bluetooth technology enables wireless music playback from the phone through the car radio. Just connect your phone to the transmitter and then adjust the appropriate radio frequency. The USB ports allow you to charge your devices (max. 3.4 A) and play music from a USB drive. Due to the microSD slot, you can play music from your portable memory card. The built-in microphone and a special call answering button serve as a speakerphone kit for making calls. The device can also serve as a voice amplifier for car navigation. All necessary information is displayed on the built-in LED display.