... 220kV AC system, electric railway, transmission line, substation, distribution Surge arrester, lightning arrester, Metal Oxide Surge Arrester, surge divrtor, surge protectorspecializes in producing 0.28 to 220kV AC system ... producing 0.28~220kV AC system metal oxide surge arresters and electric railway surge arresters with porcelain and polymeric housing for protection against over-voltage ...