Hydraulic magnetic mini circuit breaker are mainly suitable for overload and short circuit protection. it adopt hydraulic magnetic trip instead bimetal. so it has sensitivity and it  is also not effected by the ambient temperature. it is especially used for illumination and distribution in industry and commerce. they are mainly used for overload and short circuit protection within the circuit of AC 50/60HZ. rated voltage of single pole or double poles up to 240V,,three pole up to 415V. they can also be used for an unfrequent switch-over of the circuit and illumination under normal conditions. they are comply with IEC157-1973,BC4752-1977 and BS3871 part 1