This is Polyphonic Octave Generator (POG) is a classic pedal. Great for punching up a bass solo. Use it ahead of an envelope, some dirt or both and there’s no end to the fun you can have with this polyphonic octave pedal, which generates an octave up, down or both. Mix in the dry signal or split out the dry to a separate channel or effects loop. Shipped to your door, complete with 3M dual lock, for $140. Excellent used condition. (No power supply or box.) TRADE: Quality P bass parts (build in progress); quality patch cables; etc.. You can see the pedal in action here, solo and coupled with a delay: