... tank:Material of inner tank: SUS304/2B stainless steelMaterial of outer tank: SUS304/BA stainless steel/Galvanized color steelCapacity: 5L, 8L, 10L,12L, 15LFeeder tank ... is used to supply water to main tank of non-pressure or heat exchanger ... type solar water heater, when water level in main tank lower, it can supply water to it automatically, when ...