A little piece of synthesizer history here: one of the first 4MS pedals under the name "Commonwealth Collective" -- this lil noise box runs off a 9 Volt battery. Includes the pedal. Please do note, as per the previous own, be very careful turning up the gain knob, it WILL blow your amp/speakers. No joke. As per the previous owner too, in terms of support, 4MS is still happy to repair these older pedals!