heat pipe solar collector certificated by EN12975, CE,TUV, CCC ISO .New technical secret will be told to our reliable Customer. 1 Vacuum tubes : borosilicate glass 3.32 coating: Cu/SS-ALN(H)/SS-ALN(L)ALN3 Manifold casing: aluminium alloy4 Insulation: Rock wool or foamed polyurethane5 Seal material: stabilized high temperature silicon gel6 Heat pipe: copper, thickness 1mm7 Absorptivity93% ...