Langley: Mens 5.0ct Air Force Simulated Sapphire Crystal Military Signet Ring Steel, 3152 Rugged, handsome and durable Mens USA - US Air Force 316L Stainless Steel Ring Features a 5.0 carat Simulated Blue Sapphire Crystal bezel set solitaire. Made with solid Stainless Steel 316L. Made with solid 316L Surgical Stainless Steel so you know that it's made to last!