The surge arrester from Noark has a line of surge arresters that are class 2 devices. They are designed to protect against overvoltages caused by transient fast switching operations or indirect lightning strikes. It is recommended to install devices every 10 - 20 m of cable length, in main boards and sub-distribution boards. Ex9UE2 20 440 are intended for coordination with class 1 of the Ex9UE1 35 line, in the case of Ex9UE2 20 275, coordination with the Ex9UE1 35 line is carried out using a 10 m cable. The design of the Ex9UE2 surge arresters is based on varistor elements. Provides low response time. The modular design with the possibility of replacing the insert allows for quick and simple replacement of functional modules in the event of their burnout due to the frequent occurrence of overvoltage peaks.