Hammond's expression-pedal EXP-100 operates through the use of a photo-electric cell. This ensures both long-life of this accessory as well as the realistic volume-response that Hammond owners have gotten used to... The model EXP-100F (shown on the picture) also has a side-switch that can be assigned different functions (such as Leslie slow/fast) by your hammond-instrument. This pedal fits the XK series like the XK-5 model
