This is a distortion pedal from Mad Professor. I believe it was customized for bass. It's described as an overdrive, but it distorts quite heavily. I used it with a G&L L2000, a bass with a high output, and it seemed to distort as much as a Big Muff. It's a sound that suits people who like King Crimson or progressive rock. Please refrain from returns. Everything in the photos is included.