... paramaterEvacuated tube47mm*1500mm,58mm*1800mmEvacuated tube diameterouter 47cm or 46cm,interior 36cm,glass thickness 1.6mmEvacuated tube materialborosilicateEvacuated tube absorption layerabsorption layer,chemical (compound ... pressurized solar water heater Solar collector : adopt sectional metal heat-pipe vacuum tube, manifold box (SUS304-2B stainless steel for outer box),copper ...