iSimple IS31 Antenna Bypass FM Modulator for Factory or Aftermarket Car Radios Universal aux audio input for all FM radios Simply flip the switch.Selectable operating frequencies 87.9 MHz and 88.3 MHz Enjoy the clear, clean audio, Car radio aux input has a sleek, compact design Antenna bypass FM modulator, Play almost any portable device directly through your radio Audio connections and docking cables sold separately Universal aux audio input for all FM radios