The Electro-Harmonix Nano Muff Overdrive Effects Pedal revives the big sound of the 1969 classic Muff Fuzz effect in a compact, die-cast aluminum package. No complicated settings needed here: just the switch and a volume knob. Rugged construction and amazingly compact to save valuable pedalboard space! The red LED indicates when the effect pedal is switched on. You can power the Nano Muff Overdrive pedal with a 9V battery, or an optional 9V 100ma tip-positive AC adapter with an 1/8" plug.Small die-cast case saves valuable pedalboard space