16G(1.2mm) Blue Titanium IP Steel Circular Barbells Horseshoe Rings w/Spike Ends (Sold in Pairs) Metal: Titanium Ion Plated/Surgical Steel 3mm spike ends on the 5/16" & 4mm spike ends on the 3/8" Sold in Pairs 16 Gauge(1.2mm). 5/16" or 3/8 diameters available.