Solar vacuum tube 1)ISO9001:2000 ,CCC,SGS 2)Specific Absorption:92%---96% 3) ... .3 GlassExternal PipeDiameter & Thickness dia.=47±0.5mm &=1.6mm,dia.=58±0.5mm &=1.6mmdia.=70±05.mm &=2.0mmInternal PipeDiameter & Thicknessdia ... .=37±0.5mm &=1.6mm,dia.=47±0.5mm &=1.6mm dia.=58±05.mm &=1.6mm Pipe length1500mm,1600mm,1700mm,1800mm,1900mm ...