Plug-in surge arrester, according to Type 1 / Class I, for use in power supply networks between N and PE. This plug-in surge arrester (Type 1 / Class I arrester) acts as an N/PE overvoltage protector and features an ignition mechanism to trigger the response voltage. It provides protection against incorrect plugging with wrong connectors through mechanical coding of the base element and the plug. There is a labeling option for protective plugs and terminal connections on the base element. It includes two Biconnect connections for N and PE, designed for connecting round conductors and wiring bridges.