Material: The O-ring is made of 304 stainless steel, which is rust-proof, corrosion-resistant, durable, and not easy to break or deform. The surface is smooth and delicate, not easy to oxidize and fade, and it maintains a bright luster for a long time. Seamless Design: The O-rings are manufactured using seamless technology with no obvious seams or welding marks. The overall structure is strong and effectively prevents breakage caused by wear and tear at the seams. It has high aesthetics and a retro, elegant decorative effect. Easy to Use: This 304 stainless steel ring is seamless and can be assembled with split accessories such as split rings, ropes, straps, etc. The smooth edges ensure that it will not get tangled during use while providing a long-lasting and durable hold. Applications: The seamless ring has a wide range of uses. It can not only meet the precision needs of the industrial field, such as mechanical accessories and instrument connectors, but also be integrated into creative handicrafts and fashion designs, such as jewelry making, key chains, bracelet clasps, etc.; it is also suitable for home decoration, model assembly, pet traction accessories, ect. Material: 304 Stainless Steel Color: Black Inner Diameter: 40mm / 1.57 Outer Diameter: 50mm / 1.97 Thickness: 5mm / 0.2 Package Included: 4pcs x O-ring