... on vehicle brake system2.profassional Double wall or Single wall copper plated,green olive plated,zinc plated,PVF plated.... You ... optional according to customers' requirements.4. Features: No stain, smooth surface, high intensity, good plasticity, strong corrosion resistance, small resistance. ... OD: 4.0mm-18mm. WT: 0.5mm-1.0mm. Surface Coating: Copper, Zinc, PVF inner or outside.6. Coating and Lining: ...