The Control Knob is an affordable, compact, easy-to-use pedal that delivers static remote control for devices with expression control jacks. It lets you set two preset values that represent two positions of a traditional expression pedal and toggle between them with its footswitch.
The pedal’s EXP 1 Knob selects the first expression setting and the EXP 2 Knob the second. On both, fully CCW corresponds to the heel position while fully CW to the toe position. Read more here.