The over temperature protection type varistor is a series of varistors with over temperature release (disconnection) function. It is a temperature sensitive device attached to a regular MOV chip. When the power frequency current continues to increase or the MOV fails, due to the increase in power frequency current or leakage current of the MOV, the temperature of the MOV body rises to the set operating temperature of the TFMOV, and the temperature sensitive device will disconnect. This cuts off the current supply to the MOV, preventing the temperature rise of the MOV from increasing and thus preventing the ignition caused by the failure of the MOV, which is a new type of zinc oxide varistor. It uses standard leads as the output terminal, which is very suitable for installation on PCB circuit boards.