This switch is designed for use with variable speed motor drives and is available in selected 2 watt linear values. Specify the maximum resistance you want. Depressing the treadle rotates the potentiometer from zero to the selected maximum resistance. By wiring to the third terminal it goes from the maximum resistance to zero. The treadle is spring loaded and returns to the normal position when the foot pressure is removed. A SPDT auxiliary switch contact rated at 15 Amps 125-250 VAC can be added to the control. The switch will operate at the beginning of the treadle stroke.