Product Details  Energy conservation and competitive price Easy-operation and economical Renewable resources  solar collector Model:JN-C-12 Pressurized Solar Collector 1.Manifold (interior)material: red copper 2.Manifold (exterior) material: aluminum alloy  3.Tube dimensions: 58 x 1800mm / 47 x 1500mm 4.Vacuum tube coating material: AL-N-AL or AIN-SS-Cu 5.Insulation layer: polyurethane foaming or rock wool 6.Test pressure: 6 bar  7.Heat preservation: 72 hrs  8.Hail resistance: 25mm  --------------------------------Why Jineng------------------------------------ Primary competitive advantages:  1) CE, CCC, ISO9001: 2000,  2) good price and quality  3) Prompt delivery  4) Environmental Protection  5) OEM order is accepted  6) experience of export to 49 countries