1,vacuum collector tube solar water heater,solar system 2,excellent ... different sizes are a vacuum collector tube solar water heaterCertificate:ISO9001,CE,3CReliable and economic1,The ... tube : high borosilicate glass 3.3 and with 12 clad layers.2,absorptivity ≥0.92.3,emissivity ≤0.06 .4 ... prevention:72-80 hours9,frame :galvanized and plastic spraying coated/stainless steel/aluminium sheet10,packing is ...