This is an AnalogMan 2 Loop Switcher. This pedal is wired so that you have two independent loops as well as a separate tuner out. When you are on the looping side of the pedal you can be fully bypassed, have either loop on, or have both loops on at the same time. When you are on the tuner side, the loop side is disengaged effectively muting your signal. Please note that the way this is set up, the Tuner switch controls which part of the pedal you are on, so to get back to the loop side of the pedal you are still hitting the tuner switch. In some instances this may require an extra step to get to your preferred settings.