Solar keymark Solar collector Reliable, efficient, twin-glass solar tubes heat pipe Copper heat pipes for rapid heat transfer Corrosion resistant brazed copper header Fetures: 1) length: 1800mm; thickness: 0.8mm 2) the manifold: Made of red copper Conducted by heat transfer medium liquid 3) the out casing: Made of aluminum alloy mold material of high-strength with air flow design 4) water can't flow into vacuum tubes 5) resistant to high-pressure( 6bars) 6) resistant to extremely cold or hot environment 7) no harm or pollution, environment protective, clean, healthy Economic, invest once and benefit for ever 8) to assemble many collectors together for the solar central heating project of the hotel and factory are permitted. Modelabsorb a rea (m2)heat pipesupply hot water (l/)qty. Per 20/40 container (set) Diameter(mm) length (mm) no. (pcs) Free/j-1800/58-181.4458180018150/6084/175 Free/j-1800/58-201.6058180020175/6077/160 Free/j-1800/58-241.9258180024220/6064/133 Free/j-1800/58-302.4058180030260/6052/106 Whole packaging