Cylinder Nipple Stretcher WeightSold Stainless Steel with smooth finish weights with S hook. The S hook allows you to attach to larger Gauge CBRS, attach to ball weights, nipple clamps. Medium Size; 18mm x 60mm, 5mm hole 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.