Manufacture, sales, assembly and services for solar water heater, Air-source water heater;Famous Brand in China,ISO14000,ISO9001 Solar water heater Hong Shuangxi Series360° steric foaming technology, ... on cars which protects drivers, it preserves the heat for 24 hours. The water is still hot the second night.Excellent sealing ... of main unit. So customers can use it with ease. solar water heater SX18