vacuum tube solar 1.Guarantee:15years 2.Certificate:CCC,CE,ISO 3.Deliver time:Within 3days 4.Manufacturer vacuum tube solar DescriptionVacuum tube58- ... -axial structure high borosilicate 3.3 glass vacuum tube with tube wall thickness of 1.6mm.Inner tank materialSUS304-2B Stainless Steel ... for 5 years, tube and frame for 15 years1,vacuum tube length:47/1500mm,58/1800.2,vacuum tubes:15pcs,18pcs,20pcs ...