... :gradual change SS-AL-Nx/Cu selective absorption coating;life:15 year3.frame:aluminum alloy,thickness:2.0mm4.water tank:color steel ... Insulating layer,compressed rock woolHeat Pipe pure red copper TU1+water,transfer power>=150W,Working pressure,4Mpa,welding pressure 4MpaDust ... tube,High boron and silicon content 3.3,Structure,Gradual change SS-AL-Nx/Cu selective absorption coating,Vacuum Degree, ...