Boss OC-5 Octave Pedal for both guitar and bass. Bought as new, I’ve used it only once at home and sadly it doesn’t do the super specific thing that I wanted it to do- despite it being an absolutely incredible pedal in so many ways. Want the cool synth-y OC-2 vibe? Honestly, it does it better than my mate’s actual OV2 (to my ears anyway) - want a more flexible octave effect that tracks really nicely? The Poly mode is awesome and does the trick really well. For both guitar and bass it absolutely nails the octave sound. Sadly, it’s not quite for me.
eBay