high absorption rate, hail resistance, supply hot water in 24hours , anti-corrosion Evacuated tubeDia* length 47*1500mm, 58*1800mmTypeNormal vacuum tube, three high vacuum tube, heat pipeAbsorption rateMore than 92%Inner tank materialSUS304-2B, thickness: 0.4mm, 0.5mm, 0.6mm, 1.0mm, 1.5mmOuter tank materialColor steel, stainless steelInsulaton layerPolyurethane foam, thickness: 50mm, 55mm, 60mm, ...