Titanium Threadless with 3-Prong Set Opal Low Profile Top. Manufactured out of High Polish Implant Grade Titanium (Ti-6AL-4V-ELI ASTM F136). These new laser-cut low-profile titanium settings give this opal cabochon's a beautiful and perhaps more importantly - secure home. To secure the inside bar or base, add a slight bend to the pin by simply inserting the pin halfway and pushing the top to one side. Pin Gauge: 25g