I bought it because it doesn't use pots.  The volume swell is adjusted by moving an LED within the case.  The LEDs react through an opening in what they call a shutter; a piece of hard board with windows.  LED on one side and the adjustable LED (LR1) on the other side. The LED is attached by two thin malleable metal wires.  I bent the LED up very slightly and so far I'm happy with the extended swell.