... frame 1.EN12975 solar keymark 2.Anti-freezen & pressurized 3.10 years warranty Solar water heater frame Material of Model:1 ... based on FOB shanghai2.warranty:5 years for the whole system,10 years for vacuum tubes3.module design,arbitrary combination,harmonize with ... -Nx/Cu selective absorption coating,Vacuum Degree,P<=5*10-4,Service Life,10 years Mounting FrameAluminum Alloy,Thickness,1.8 mm ...