Designed to be stacked in front of a fuzz pedal of your choice turning it into your own specialised Octave-Fuzz. The Upper is a second-harmonic generator, producing analogue octave up with subtle ring modulation. Depending on interval, you'll either get a perfect octave up tone, or octave mixed with a very subtle octave down harmonic, or a dissonant tone. Special-ordered with a foot-switchable true bypass loop for quick-stacking with other pedals. Made in the USA.