This lab series #24 is based on the Doom Bloom, a modern silicon fuzz with a lot of controls.
The Doom knob is the magic of this Fuzz, that knob increase fuzz and definition of the tone. The way it act keep your tone clear even at lower tuning or higher distorted level.
The Bias is acting the way you would expect, combined with the Doom, you'll get that nice "Fuzzy Velcro Tone".
The overall EQ is controlled by the Body (Low EQ) and High knob. The Head control the overall volume available.
Link to the production model here : Bee Fuzz