Circuit breaker is used in lighting distribution system or motor distribution system for protecting overload and short circuit in the system. The product is neoteric in structure, reliable and excellen t in performance. Its frame and parts adopt plastics of high fire resistant and waterproof. The product, with long life, is mainly used in AC 50Hz/60Hz single pole 240V or two, three, four poles up to 415V circuit for overload and short circuit protection, as well as for unfrequently switching electric equipment and lighting.