This protector heater, also known as a high limit thermostat, is a genuine OEM part. Its function is to keep the heating coils from getting too hot by providing and automatic shutoff, which is an important safety feature in your appliance. When replacing the high limit thermostat, make sure to first unplug the appliance, and wear work gloves when completing the repair.
This part, in conjuntion with the diode and capacitor, can increase voltage from primary to very high in a short period of time and it converts that high voltage into waves of cooking energy.