Steel Basicline® Silver Sun Tunnel The Flesh tunnel of the Steel Basicline® is made of premium processed material. It is externally threaded, the ring is screwed on to the outside thread of the tunnel and ensures a perfect hold. The front of the tunnel is made of sterling silver and has a sun ray design.All tunnels of the Steel Basicline® are sterilisable, and due to their skin friendly material harmless to allergic persons. As an experienced person in the matter of gentle stretching, this tunnel is absolutely the right choice for you. The flesh tunnels are available in sizes 10.0 - 16.0 mm (in steps of 2).