This used FatMetal Pro is designed for players who wanted a warmer metal tone that works better with brighter guitars and amps, but also is less aimed at palm-muted metal, and works better for tremolo-picking Black metal, and darker sludge and doom metal tones. All features are identical to the TightMetal Pro, but the tone has been tweaked to extend the low range of the Tight and Tone controls, and the Black Gain switch boosts the gain in an appropriate way to get the thicker, buzzier gain required for those genres.

The Thrash switch converts the basic tone into a heavier, more mid-scooped tone for classic vintage metal tones. The noise gate has also been retweaked to make it smoother, and to sound better with the reduced highs of the FatMetal to allow it to work better for solos....but it's internally adjustable if you want the TightMetal CHOMP gate, just crank it!