Rated for NEC Class I Division 2 locations, 165 W Mercmaster III delivers 100,000 hr of virtually maintenance-free operation. Unit includes corrosion-resistant materials and operates safely in temperatures down to -50°C. Mercmaster III is designed for industrial, chemical processing, and refining operations where flammable gases and vapors are present, as well as nonhazardous locations subject to extreme weather and excessive dirt and moisture.