Titanium Threadless Synthetic Turquoise Tops is manufactured out of High Polish Implant Grade Titanium (Ti-6AL-4V-ELI ASTM F136). This special top has a prong setting and a flat back so it can sit flush on the skin especially for nose and cartilage piercings. Compatible with any bar or base in any gauge. Available sizes: 2.5mm, 3mm and 4mm. Pin Gauge: 25g.