This Black PVD CZ Flat Disk Captive Ring is crafted from 316L stainless steel. It is sold individually, with a black PVD finish and a clear CZ gem for a unique and stylish look. Available in sizes 16G to 2G, with inner diameters of 5/16", 3/8", 1/2" and 9/16". For 8G and bigger sizes, ring openers are recommended. The gem sizes are 3mm for 16G, 4mm for 12G and 10G, 5mm for 8G, 6mm for 6G, 7mm for 4G and 8mm for 2G.