Reverb Pedal Accel"Classic Reverbs" Guitar Effects Pedal No nonsense reverb pedal with an array of rich full reverb effects! True Bypass design. Power Source: 9v battery, DC9v adapter or 9v power supply (not included) Controls: Blend, Time. Top Toggle Switch: Three modes; Hall, Spring, Room. Bottom Toggle Switch: Tail Long / Short. For video sound demo's search "Accel Classic Reverbs pedal" on Youtube