... Solar Keymark certificate 2. Flat plate collector solar flat panel:1.reliable,efficient,twin-glass evacuated tubes2.red copper heat ... competitive.model:150L,200L,260L,300L,400L,500LMaterial:flat panel:copper material,cooper cover coating of blue titanium which ... panel with ANS1297-1-1975,BS6206A AND JIS R3206standards,toughness with AS2208-1978 and federal standards of united statespanel insulation: ...