... CE,CCC,ISO9001,ROHS ,SK,certificates! 3.OEM is welcomed! 4.Factory only, not trading company. low price and high quality solar water heaters ... water, a cycle created in the tube which hot water ascending and cold water descending status. Keeping natural circulation like this, the water in ... roof, flat roof optional.Fastening pieces:Made of zinc-coated stainless steel.. ModelTube ...