... .Delivery:7-20Days 4.OEM,2500Sets/Month vaccum tube solar water heaterInner tank:Food grade SUS304/2B ... /162/180/216/270/288/306/324L.Vacuum tube:3.3 high borosilicate glass, 1.6mm thick ... 47mm or Ø58mm and length 1500or 1800mm, resisting 28mm hail.Tube quantity: 15, 18, 20, 24, 30, 32 ... Improved polyurethane integral foaming with 50-65mm thick.Bracket:Galvanized steel with 1.50mm thick.Or stainless ...