Hit the road with the ultimate driving companion: Monster FM transmitter equipped with dual-port USB charging and immersive 3D sound and RGB LED.This nifty device bridges the gap between your car's radio and your personal music collection on your smartphone or MP3 player. Just ...Hit the road with the ultimate driving companion: Monster FM transmitter equipped with dual-port USB charging and immersive 3D sound and RGB LED.This nifty device bridges the gap between your car's radio and your personal music collection on your smartphone or MP3 player. Just plug it in, tune to an unused FM frequency, and voila – your favorite playlists, podcasts, and audiobooks are broadcasted directly through your car's speakers, all while keeping your devices fully charged.