... CCC,CE,ISO 3.Deliver time:Within 3days 4.Manufacturer evacuated glass tube DescriptionVacuum tube58-1800mm co-axial structure high borosilicate ... years1,vacuum tube length:47/1500mm,58/1800.2,vacuum tubes:15pcs,18pcs,20pcs,24pcs,30pcs3,Outer tank material:202stainless ... the many residentbuildings.Working principle:1,The high quality vacuum tubes ansorb the solar ultraviolet ray;then heat the cold water ...