For protecting consumer systems against transient overvoltages caused by indirect lightning strikes and switching operations, test class II according to IEC 61643-1+A1, SPD-type T2 according to EN 61643-11, auxiliary switch SPC-S-HK can be attached for remote signaling, can be busbar mounted with all Xtra Combinations switching devices caused by indirect lightning strikes and switching operations, test class II according to IEC 61643-1+A1, SPD-type T2 according to EN 61643-11, auxiliary switch SPC-S-HK can be attached for remote signaling, can be busbar mounted with all Xtra Combinations switching devices