The potentiometer in the Ernie Ball VP JR 250K has a 250k ohm resistance suitable for the audio path of passive instruments. Behind the jack area under the footplate is a micro taper switch which provides the user two distinct volume swell rates. Overall Volume Pedal Junior dimensions: 3.5" W x 10" L x2 3/8" H . The main pivot shaft is of centerless ground 1/2' diameter stainless steel, precision seated though nylon bushings at both ends. Tough long lasting Kevlar cable transmits pedal travel to the controls and is attached by stainless steel springs.