EarthQuaker Devices A/B BoxThe EarthQuaker Devices A and B Box Utility Pedal is a simple tiny tool that lets you choose between two of almost anything. Because of its completely passive design, there is no circuitry between the input and outputs which means it can be used in both directions. Use it to switch between two amps. Switch between two channels on a multi channel amp. Use it as a tuner out and mute switch. Switch between two instruments. Run a dry path and a wet path.