All of the appearance of a captive bead ring with none of the hassles.
Material specification: 316L surgical stainless steel
Ring gauge x internal diameter:
4mm x 10, 12, 15, 19, 22mm
5mm x 10, 12, 15, 19, 22, 26mm
7mm x 12, 15, 19, 22, 26mm
8mm x 12, 15, 19, 22, 26mm