Electro-Harmonix - Sovtek Green Russian Big Muff π - knob

Sovtek Green Russian Big Muff π – Knob

Designed to fit a 1/4" diameter, smooth, full-round shaft. If you're restoring an original pedal and the stock pots are still functional, you can use a 1/8" adapter to ensure compatibility. Simply ream the knob's shaft hole slightly with a needle file, and the adapter will fit securely in place.