KI66 universal and enhanced serial thermal protectors are widely used in industry, electrical household appliance and electric equipment to avoid abnormal operation caused by overcurrent and overtemperature. The products provide effective, reliable and safe protection. The enhanced casing is suitable for internal installation of plastic hermetic motor, which can bear the plastic molding pressure at 3.5Mpa. The performance of the products satisfies the standards including IEC34-11, GB13232, GB/T13002, etc.