This is a hybrid GE/SI fuzz that is not based on a fuzz face.
There is a hi/lo tone switch that toggles between bright and deep settings.
There is another switch that provides some gating effects in the up(G) position. The fuzz is a little nastier in this position as well. In the down position, there is no gating and the pedal is smoother sounding. With the switch and fuzz knob down, the pedal can be used more like a boost.