The MXR Poly Blue Octave M306 electric guitar effects pedal generates monophonic or polyphonic octave/fuzz tones.
You have two options that really take the original circuit to the next level. Two buttons let you operate the pedal in monophonic or polyphonic mode, and activate/deactivate the fuzz circuit.
The M306 Poly Blue Octave also lets you control the level of four distinct octaves via dedicated settings (Sub-1, Sub-2, Oct+1 and Oct+2).
In monophonic mode, you get effects reminiscent of various analog pitch-shifts (MXR Vintage Bass Octave, Octavio Fuzz). With an optional expression pedal, you can control various parameters in real time.