TDK Corporation's EPCOS SNF series of disk MOVs are designed for enhanced resistance against heat and humidity and for use in harsh environments. Maximum operating temperature is increased significantly to +125°C due to the use of a silicon resin coated design. The series are tested according to IEC test methods under 60068-2-x for climatic sequence, rapid change of temperature, and damp heat to verify performance. In addition, the entire series is specified to less than a 10% change in 1 mA varistor voltage after exposure to +85°C and 85% relative humidity with 85% of varistor voltage applied for 1,000 hours. These characteristics are appropriate for applications in which the electronics they protect will be exposed to ambient conditions more representative of outdoor applications like smart energy meter, solar inverters, LED lighting fixture, electric car chargers, and others.