... :Product DescriptionTO-B series surge protective device(in short:SPD,alias:surge protector,surge arrester)is suitable for ... a failure release mounted on the module of surge protective device,When the SPD fails in breakdown ... 150,TO-B-120,TO-B-100 series surge protective devices are suitable for B grade ... by the thunder.TO6-80,TO6-60 series surge protective devices are usually installed in low voltage ...