Class IClass B lightning arresters are mainly used in lightning protection zone (LPZ) 0 to 1, widely used in building entrance lines(such as distribution box), elevator, mineral, oil equipments, power transmission and so on. Class I lightning arresters adopt unique designed seal construction with multilayer spark gap, no spark emission outside the housing. Suitable for grounding system TN-C, TN-S, TT and IT. With working status indication window, and remote control contacts. High impulse discharge current, Iimp value is 25kA, 50kA