Great little device and highly surprised at its small form factor.
Place it into cigarette lighter receptacle, turn on your device's Bluetooth, connect and tune your car radio to FM 96.4. Can also download the Roidmi App to adjust the FM frequency between 8.75 – 100mhz and an option to reduce the background noise but its not as dramatic as people are reviewing.
Pros: Small footprint, works on all cars with an Cigarette lighter receptacle and FM radio reciever, plug and play, Android/iOS app for car voltage checking, reducing static and FM frequency adjustments, Charging ability and can change LED color inside app or just turn it off completely. Cons: Receives calls through car radio but mic is used on the device, quality of music can deteriorate if the device is turned up too loud.