Black PVD Titanium Internally Threaded Double Flare Basic Tunnel. Sold by piece. 8mm wearable surfaceTitanium tunnels are a durable & light-weight material great for everyday & long term wear. The internally threaded double flare allows for an irritation free experience during insertion & removal with the threaded end screwing off. The double ended flares provide a secure fit and help keep the jewelry in place. Made from implant-grade titanium Ti-6AL-4V-ELI ASTM F136 and coated with Titanium Nitride (TiN) using the Physical Vapor Deposition (PVD) process.The PVD coating bonds at the atomic level to the titanium, creating a chemically inert and nickel-free surface that won’t flake, leach, or irritate the skin. The same technology is used in medical and aerospace applications for its safety and stability.