1.Heater: Hard borosilicate glass vacuum tube.2.Inner water tank: imported SUS3042B food grade stainless steel.3.Out water tank: galvanize aluminium zinc.4.Heat preservation layer: imported polyurethane5.Plank: galcanize steel spray-mold.6.Vacuum tube diameter; 47mm,58mm,70mm. 7.NO. of tubes: 12pcs,15pcs,18pcs,20pcs,24pcs.Website:www (dot) ahgreatsun (dot) com
solar water heater