... selective absorption coating;life:15 year3.frame:aluminum alloy,thickness:2.0mm4.water tank:color steel plate thickness:0.5mm outertank ... ,300L,400L,500L,600L,700L,800L............solar water collector1) Reliable, efficient, twin-glass evacuated tubes2) Red copper(TU1) heat pipes for ... to be highly competitive.NOTE:1.above prices are based on FOB shanghai2.warranty:5 years for the whole system,10 years ...