Got this built from Mike at Rhythm & Detonation. Great pedal but need to unload some stuff to pay for things I have coming in. Asking $70 shipped. Here is the description: "This is a 4 knob rat with bass mods. The bass mods involve doubling the input cap and the low frequency roll off cap to allow more sub frequency to pass through. This is handy if you use the pedal for bass or extremely downtuned guitars. The 4th knob is the ruetz mod which is a 500 ohm pot that replaces the 47 ohm resistor that sets the gain for the low-end frequencies. With the pot turned fully clockwise the low end is cleaner and more defined with less fuzz and distortion. When the Ruetz knob is turned counter-clockwise the low end gets fuzzier and nastier. This is a great mod for bass because you can maintain a tight low-end while still having plenty of grit on the treble and attack."