This is an octaver from the Guyatone Mighty Micro series. It allows adjustment of the original sound, one octave down, and two octaves down. While it's called an octaver, it's not like the modern ones that are clear and responsive. It's closer to the lower octave fuzz sound of older Japanese octavers. Of course, it doesn't handle chords well, so when you play chords, the pitch will behave erratically. It's not an easy-to-use effector, but conversely, it has a unique sound that you can't get with current equipment. Depending on the settings, it can produce 8-bit fuzz or bit-crush-like sounds, so it's recommended for special effects use. I checked it before listing, and there were no functional problems.