Skip semicircle opal titanium clicker images slider SKU: Semicircle Opal Titanium Clicker Sign-up to see price This 16g Opal Titanium Clicker features an 8mm inner diameter and has a semicircular cut of synthetic opal. Product Details: Material: Titanium 6Al-4V-Eli ASTM F-136 Gauge: 16g (~1.2mm) Inner Diameter: 5/16" (~8mm) Opal Color Options: Blue, White 13 anodized color options