The 250k Mono Volume Pedal from Ernie Ball utilizes a 250 kOhm potentiometer which provides a suitable resistance for the audio path of passive instruments and their electronics. The internal taper switch provides two distinct volume swell rates. The main pivot shaft is made from center-less ground 1/2" diameter stainless steel and precisely seated through nylon bushings at both ends. The large center shaft has a large diameter, which provides strength and creates a broader stress bearing surface.