One thing to keep in mind, however, is that this pedal basically sounds horrible. It's primary purpose is to cut through. But like a wild man with a machete, it is not nice.
Knobs are In, which is drive; Limit, which clips the original waveform off at about the same size as the harmonics (if you want); and Out or Volume, which is output level. If the Limit knob is set to the right, the signal remains unclipped.
You'll notice the dynamic response is higher than most pedals. If you put a tremolo pedal set smooth in front of it you'll hear it sweep through it's wild frequency multiplying stages, or if the trem is set for square wave it will jump back and forth between crunchy harmonics. Conversely, you can get ringing harmonic effects using a dynamically freezing pedal in front of it like a compressor. The biggest drawback to this pedal is that of anything in your arsenal, it's the most likely to get you kicked out of the house by your mom, girlfriend, boyfriend, or wife. Or roommate or Dad. Or Grandma. Even your dog. Whine. Keep in mind that this pedal needs to see a sloped wave in order to do it's thing, so an undistorted guitar signal going into it will allow it to generate the strongest harmonics.