This is an emulation of an Dallas Rangemaster with added controls for tweaking or for use as a full-range booster, an overdrive, and more. It runs in mono or stereo, and has 2x oversampling (always on).
The Rangemaster was a Germanium transistor treble boost developed in the 1960s. It and similar effects have been used by Eric Claption, Brian May, and many more great guitarists. It's most often used to drive a distorted tube amp into more distortion, while boosting the upper-mids for a screaming lead sound.