Compact flat-plate solar water heaterSpecification:1.inner tank:1.5mm sus304-2B food-grade stainless steel2.outer tank:0.4mm colorful steel3.insulation:50mm high density ployurethane foam layer4.all copper pipe5.bracket:1.5mm galvanized steel6.hail resistance:25mm7.heat preservation:72hours8.capicity:300L