HM003 solar water heater is designed with three high vacuum tube by adopting patented technology of interference coating film. So it features high absorption and great heat-collection. Due to application to superior quality of raw materials, high quality of solar water heater is ensured. First, both inner tank and water tank is made of 0.5-millimeter-thick steel. Inner tank uses SUS304 stainless steel while water tank uses powder coated galvanized steel plate. Second, as a key component, vacuum tube of solar water heater is manufactured with Model 3.3 borosilicate glass. Third, the frame of solar water heater is devised with powder coated galvanized steel plate, 2.0mm in thickness. Last but not least, insulated function is perfectly achieved because of application of polyurethane foaming.