solar water heater : certification:ISO9001,ISO14001,CCC,CE,Solar Keymark solar water heater:heat pipe tube pressure:pressuriz solar water heater: material:1.volume of storage tank:120L,180L,240L,300L2 ... -off molding polyurethane foam with thickness 50-65mm,4.Suitable for campong area,holiday residences.5.no vent and less heat ...