... High efficiency solar collector using heat pipe evacuated tubes 2) Able to be used in all climates ... 3) Reliable and efficient with twin-glass solar tubes 4) Copper heat pipes for rapid ... heating capacity 13) Tubes easily replaced if broken, can be used with broken tubes 14) Ideal for ... :1.CE,UL,ISO9001,CCC,Solar water heater with SOLAR KEY MARK certificate2.High efficiency, Absorption rate ...