... Solar Keymark certificate 2. Flat plate collector solar flat panel:1.reliable,efficient,twin-glass evacuated tubes2.red copper heat ... popes for rapid heat transfer3.attractive design,standard frame suitable for pitched roof or flat roof4.significant advantages ... competitive.model:150L,200L,260L,300L,400L,500LMaterial:flat panel:copper material,cooper cover coating of blue titanium which ...