Solar water heater 1)ce&solarkeymark&ccc for solar collector 2)15 years warranty 3)easy installation, adjustable bracket Features: 1) Simple structure, with copper coil heat exchanger inside, coil oil in tank, good in anti-corrosion2) 18 tubes/set, capacity of 150L3) 20 tubes/set, capacity of 165L CE solar water heater--Compact Pressurized Solar System