What we got here is supposedly related to the Fuzz Face but with so much fatness and nastiness it's a distant cousin at best. This one (from Fortin) is its own thing, and all the better for it. You can think of it as a two knob fuzz with an extra knob, because that "girth" control ain't no simple tone knob, it adds serious low end and changes the whole game. Pretty simple inside with a pair of neatly biased BC550 transistors and some fat capacitors, this takes a boost really well and plays happily with your other dirt pedals. It's got a decent selection of tones within it too - but excels at being nasty, on guitar or bass.
Hand soldered (with lead) onto a pcb with quality knobs and a solid, true bypass footswitch. Needs a standard 9v centre negative power supply (sorry, no room for a battery). Return it if not satisfied, or if it ever needs repairs.