The Hager SP120 is an electronic surge arrestor that provides protection against the effects of transient voltage spikes, surges and lightning strikes. It is Type 1 compliant, has one pole, a nominal current capacity of 50kA, a DIN rail attachment for easy installation, and an IP20 protection rating. The discharge voltage rating is 4kV and it is suitable for use in TN-C-S, TN-S and TT power systems.