“Level” controls volume (right is louder, left is quieter). “Distort” controls the amount of hard clipping distortion (right is more distorted, left is less distorted). The side push switch allows the player to toggle between two versions of the circuit produced during its fifteen-year history: Germanium mode (“Era 2” version) and Silicon mode (“Era 3” version). The footswitch activates the pedal via soft touch bypass switching. The status LED indicates the circuit is active.