This is the original POG by Electro-Harmonix, the octave pedal that gave birth to the POG 2 and the POG Nano. With the original POG, you can add up to two octaves up or one octave down to your signal and blend them together to your taste with each voice's separate volume control. An added lowpass filter with switchable resonance gives you even more control over the tone and voicing you get from the POG.