... , ISO certificate 2, OEM project 3, vacuum tube nonpressure solar water heater 4, 3 years warranty 5, 13-year service Integrative Non-pressurized Solar Water Heater / KD-NPBMaterial:A ... for solar water heater, 1 year warranty for automatic controllerPackaging: Vacuum tube / carton (for sample order wooden box packing is required), water tank / carton, Integrative ...