Our 110kV, 220kV, 550kV series tank type metal oxide surge arrester for GIS has high protection level, advanced technology, high reliability, long repair cycle, little maintenance work, prompt installation, low running expense etc. Characteristics. Our tank type surge arrester has excellent steep respond characteristics, especially lower steep impulse residual voltage, this is advantageous to GIS equipments with even voltage/time characteristics. Our tank type products has reached advanced world level.