The MXR Distortion III was developed by Dunlop giving you sweet subtle overdrive to massive heavy distortion. It has a natural amp like quality that is versatile to any playing style. The Distortion III has three knobs (Output, Tone and Distortion), an LED, side mounted input/output jacks and a heavy-duty footswitch all packed into a sturdy metal housing. This pedal runs on a 9v battery or power supply (not included).