Damnit This Sixth Sense Hexagonal Glans Ring made of quality surgical steel and available in 4 sizes.. approximate measurementsSmall: 25mmMedium: 28mmLarge: 30mmXLarge: 32mmBall size: 9mmRing thickness: 3mm This product is certified 100% Non-Magnate and medical-grade steel. Beware of cheaper products that are not solid surgical steel but chromed steel or poor quality surgical steel that contains Magnate. Magnate is the ingredient that makes steel rust. We will only include this endorsement on our 100% surgical steel products.