This series of products are suitable for AC 50/60HZ, rated working voltage 230/400V three-phase power distribution system. It meets SPD class II test, the maximum discharge current of class II protector is up to 40kA, suppresses direct lightning, induced lightning or other transient over-voltage, discharges the surge energy to protect the system circuit and load equipment. It has the advantages of class I and II protection, large discharge capacity, low residual voltage, no leakage current, integrated modular structure, easy installation, high safety factor, long service life and so on.