Extension/spare part module for QuickFlex sockets. The integrated surge protection module protects devices connected to the socket from voltage peaks in the network. The module also protects sockets that are within a radius of 5 m on the same circuit. With visual and acoustic fault indication: After an overvoltage, the green control LED goes out and a signal tone sounds when the plug is plugged in. A central plate with a lens is required for the visual indication. Surge protection device (SPD) in accordance with EN61643-11 Type 3.