... fashionable design, Keymark, CE, Main features of all glass evacuated tubes solar collector:Manifold: aluminum alloy Head pipe: copper Insulation layer: ... Ø58 x 1,800mm Number of tubes: 20 pieces Collector area: 2.88m² Tube vacuum degree: 5 x 10 ... piecesFor more details about our all glass evacuated solar collectors, please check our website, or email us. all glass evacuated tube solar collector