A simple no frills octave pedal that has the ability to add 2 octave tones to your guitar signal. Along with your original signal the OC-2 adds one octave below your signal and another one octave below that one. Each tone has it's own seperate volume control which allows for some incredibly thick sounds, unison type playing, and even synth-like lines. The tracking on the OC-2 is surprisingly accurate and even quick runs and staccato notes hold up well. Unless you're hell bent on complete low-end mayhem, I'd stick to single note work when using the OC-2 as chords tend to disintegrate into a unregognizable rumbling of mush. This is really a great addition to any rig if only for some occasional sub woofer damage. This dependable brown box has been in the Boss lineup for years and I can certainly see why they keep cranking 'em out.