Here is what Mike says...

'One Knob Overdrive / Distortion ..Fuzz, based on the Electra Distortion and Alan Yee - Fuzzy Nuts (Mythos -Golden Fleece) style circuit. Interacts nicely with your guitar volume, backing off the volume gives a nice crunchy overdrive, dial it up and get a great distortion drive  .. bordering on fuzz territory. 

Runs on external 9v, centre negative, sleeve positive pedal power supply (not included). Check out the sound clips on @mikeriversguitars YouTube channel.'