The potentiometer has a 250k ohm resistance suitable for the audio path of passive instruments. Behind the jack area under the footplate is a taper switch, which provides the user two distinct volume swell rates. Overall Volume Pedal dimensions: 4" W x 11" L x 2 3/4" H. The main pivot shaft is of centerless ground 1/2' diameter stainless steel, precision seated though nylon bushings at both ends. The large center shaft diameter, in addition the strength factor, creates a broader stress bearing surface.