solar water tank Inner tank material: SUS304 food grade stainless steel plate, the thickness is 0.4mm,0.5mm,0.6mm. solar water tank:details:1. Outer tank material:Powder coated color steel sheet.2. Inner tank material: SUS304 food grade stainless steel plate, the thickness is 0.4mm,0.5mm,0.6mm.3. Heat Preservation layer: 50-65mm improved polyurethane integral foaming, superior heat preservation.4 ...