The CC-1 from Kurzweil is a continuous control pedal for use with keyboards and other instruments. Plug it into a compatible jack on another device, rock the pedal back and forth, and the assigned parameter will be controlled. The assigned parameter could control the volume, the spin of a speaker emulation, etc. The CC-1 features a rubber top to keep your foot in place.
Single 1/4" stereo (TRS) connector
10 k Ohm, linear-tapered potentiometer