... 3.High anti-corrosion tank 4.OEM available Non Pressure Compact Solar Water Heater System Shell: Adopt new type color plates; the ... resistance to extreme cold and heat.High-efficiency Heat Preservation System: Imported foaming machine, 360° three-dimensional homothermal polyurethane ... anti-freezing, timing water delivery, automatic water delivery. Non Pressure Compact Solar Water Heater System