FIREMAN is based on the legendary amplifier builder's famous distortion pedal. It's a very amp-like distortion pedal with Modern Brown Sound. We designed it with 2 independent VOLUME, GAIN control knobs to fit rhythm and solo applications. FIREMAN offers a True-bypass / Buffer-bypass toggle switch,  and a 9V / 18V toggle switch. The 18V position doubles the working voltage inside to give you wider dynamic range.

https://www.nuxaudio.com/fireman.html