Low voltage metal oxide surge arresters with a silicone housing NNO and MOSPO are designed for installation in low voltage power lines or junction boxes with voltages up to 1 kV.They serve as the initial level of protection against surges and other transients. The varistors of low voltage surge arresters NNO and MOSIPO are directly molded by silicone rubber, providing them with a high level of ingress protection rated at IP 67.