(1) Genuine Fender/CTS 250k/500k dual concentric "stacked" audio taper potentiometer. Allows for volume and tone controls in one 3/8" mounting hole. Top shaft is 3/16"(4.75mm) diameter and bottom shaft is 17/64"(6.75mm) diameter. Includes nut and dress washer. Correct value for '62 stack knob Jazz Bass®, top knob 250k and bottom knob 500k.