Stunning gold PVD coated surgical steel flesh tunnels. PVD coating with internally threaded screw fit flare for easier insertion. Physical Vapor Deposition is a process that coats a base material, in this case, 316L Surgical Steel giving a desired colour or finish - basically, it makes steel look sexier. Extremely accurate gauge size. Hard-wearing, low friction gold PVD coating. 316L premium-grade steel.