The first version of this pedal was based on the Tube Sound Fuzz, and this revised unit builds on those strengths.
Also, though it’s not based on a ProCo RAT, the name hints at it for a reason - with the gain rolled up it does a pretty good impression of RAT crunch.
The bias switches between class B and class A amplifier operation, though you’ll probably end up staying in class A territory based on the sounds on offer, even if it is a bit noisier.
With the gain and treble rolled back, there are also smooth low-gain lead and rhythm sounds on tap, though a bit of experimentation is required to find them.