solar water heater 1.ISO, CE, CCC ... copper 12mm diameter, 1.0mm thicknessDescriptions: DescripitionPre-heated solar water heaterMaterial of out tank0.4mm thickness white color ... SteelStructure of tank:5 holes for air vent,overflow,water inlet and outlet,electric heaterWelding: ... -M470202.50581800202003,4367690MXR-M470-243.00581800242404347082Feature:1.Use the copper coil as teh heat exchanger, according ...