Specifications: For closed loop manifold system, I would like to explain as follows: A. It is closed loop high pressure system, can bear pressure of 6 bar. B. Working principe is the same as flat solar panel, solar heat the heat transfer medium in the heatpipe, it began vapourize and heat to the end, the end will conduct the heat to water. C. Insulation use rockwook, which can bear high temperature of 350C, and will not be hurt. D. Use SC vacuum tube, have better heat efficiency, and would highest reach 350C. E. Anti-freeze heatpipe, can resist low pressure of -35. C, this system has been used in Sweden for 3 years.