The Schneider Electric iST 4P 40R is a Type 2 (Class II) Surge Protective Device from the Acti 9 iST series. Designed with a 4-pole (3P+N) configuration and a built-in remote signaling contact ("R" version), it provides protection against transient overvoltages from indirect lightning strikes and switching operations in three-phase electrical systems, with the added capability for remote monitoring.