Synthetic Opal Stone IP 316L Surgical Steel Captive Bead WildKlass Ring (Sold by Piece) Synthetic Opal Stone IP 316L Surgical Steel Captive Bead WildKlass Ring (Sold by Piece) Lightweight and comfortable to wear. Material: 316L Surgical Steel 16 GA, Length: 8mm, Ball: 3mm, Rainbow Exceptionally High Quality Jewelry!