skeleton frame system adopts high quality hot dig galvanized steel,all accessories all adopts use first welding then galvanized quality assurance 20 years,zinc attached bigger 490g/m2,thickness bigger 70 micrometer all accessories in site installation,connection fittings and tight fittings 20 years no corrosion. covering materials: covering materials separates solar panel,single layer glass,hollow glass etc,average adopts aluminum alloy materials and rubber strips installation and sealing,ensure greenhouse have good sealing function.Alluminum alloy all by special passivation dealing,compare with ordinary aluminum alloy have better anti-corrosion functions thin film:PO film,PET film etc,8-15 silk,assurance 3-5 years sun light panel:outside anti-UV,inside anti-water condensation,have good translucent,good keep warm ability,good strength,good hardness,good toughness,and good anti-impact function,assurance 10 years single layer glass:ourside have beautiful appearances,have good sun toughness,but keep warm ability and proof heat ability cant compare with sun panel,assurance 10 years hollow glass :have beautiful appearances ,toughness good,keep warm function compare with glass don't have big difference,quality assurance 10 years