I order replacement knobs from Appliance Parts Pros online. The knobs arrived quickly and they were a perfect fit. I took the one knob that I salvaged to a local appliance repair store the man at the store looked it up on the computer and told me that he needed the serial number. I went home and went on line, found Appliance Parts Pros website entered the number that was on the knob, looked at the picture. I ordered the knobs and the rest is history.