... certificate ,ISO9001-2000 2.15YEARS warranty for vacuum tube 3,MIN 1set CE certificate non pressure solar water heater 1 ... : polyurethane foam, thickness:55mm;4.vacuum tube: high borosilicate 3.3, ,58mm*1800mm;5.bracket: galvanized and plastic spraying coat, ... 12 layers of spattering deposition of trivalent technology,high borosilicate glass,gradual change of SS/CU selective complex absorptive coating. ...