The Dark Boost is designed by Devi Ever and licensed to FuzzHugger(fx). Here's all the details from them...
From boosting, to bass boosts, to surprisingly fat, full, and creamy drives! Fattens up
thin and bright guitars (and amps) unbelievably, adds huge dimension and bass to any
setup (guitar or bass)! The new Dark Boost features a third knob, giving you control
over the pedal's voltage, for even more control over texture and response! Features
Boost and drive with big bass.
Fattens up bright guitars and amps.
Overloads bass rigs in the sweetest kind of ways.
Works well with bass, guitar, vocals, synths, drums, and anything else you can run
Ctrl: Changes boost intensity and texture.
Volt: Lowers voltage applied to the circuit for control over texture and response.
Vol: Your master volume and boost control.
Controls: Ctrl (Intensity), Voltage, and Volume