Spikes Two Tone Grooved 2-Part Spinner Gears Black IP Stainless Steel Ring Stainless steel is corrosion resistant and will not tarnish. It is a very strong and very durable metal. Material: High Quality Grade 316L Surgical Steel Comfort Fit - Contoured on the inside for a comfortable fit. Width Size: 8.8mm Wear it for any occasion! Exceptionally High Quality Jewelry!