Modular surge protectors are developed to meet overvoltage protection needs for low voltage networks. These overvoltages are mainly generated by lightning although also industrial changeovers and network failures. These protections are designed to be fixed on a symmetrical DIN rail and easily adapt to standard electrical panels or cabinets. Combined transient and permanent protection models, and compact transient models are especially suitable for updating existing installations. Our protector technology combines high energy varistors with specific gas dischargers.