Mighty Therm, Cupronickel Tube Assembly, Indoor Boiler (8 Tubes), 1010, Laars Code Compliant ASME Tube Assemblies, Built in accordance w/the requirements of the ASME Boiler and Pressure Vessel Code, Cupronickel tubes w/bronze tubs, a non-ferrous solution for the most demanding systems. Suitable for higher oxygen content hydronic systems, all volume water applications and excellent for swimming pool heaters.