... of EPDM,1.Light, flexible, closed cell, synthetic caoutchouc;2.Free of PVC, CFC. Material class: B2 according to DIN ... 52613Corrosion of Copper ,Stainless Steel NoncorrosiveDIN1988Environment Friendly CFC ,HCFC free UV, Weather ResistanceExcellent Flexible Stainless Steel Corrugated PipeMaterial SUS304/316LOuter ... .0200.312 Pre-insulated Solar Flexible Stainless Steel Pipe System with UV Black Film