The BYOC Mouse is a modified version of the original Proco RAT. It has level, distortion, and filter knobs just like the original, and a 4th presence knob. This is a popular mod for the RAT circuit. It is often referred to as the "Ruetz mod". It also has a 3-way clipping switch. It has silicon clipping, like the original Vintage RAT, LED clipping like the Turbo RAT, and Schottky diode clipping for an even more saturated "fuzzy" RAT sound. Comes with an NOS LM308 chip just like the original for that vintage RAT tone.