1)heat pipe solar collector 2)vacuum tube:70X2100mm 3)with SOLAR KEYMARK AND SRCC ... 1)Manifold and frame: Stainless steel or aluminual alloy2) vacuum tube with heat pipe inside;3) Manifold with copper ... thickness, 1700mm length, or OEM.5) Vacuum tube:Two target or three target vacuum tube, 47*1500mm, 47*1800mm, 58 ... resistance: 25mm;For more information, please contact us! vacuum tube solar collector