High Efficiency Surge Protections are designed to protect systems and electrical devices against pulses and transient overvoltages determined by atmospheric origin and electrical operations. These are used in the lightning and overvoltage protection systems between the Lightning Protection Zone 0A (LPZ 0A) and LPZ 1 (please refer to the image below). This kind of SPD has to repeatedly conduct partial lightning currents with 10/350 μs waveform preventing their propagation into the electrical installation of the structure.