Spring O-Rings, also called Snap Clamps or Key Chain Rings, are used everywhere imaginable. You'll find them in bags, wallets, camera bags, bridle caps, dog collars, belts, camping gear, hiking gear, and just about anything else you can think of. These rings are made of metal and are professional quality robust and very easy to apply. Special coating has been applied to make shiny, smooth metal rings. You can view our other buckles and ring accessories here. Presented in standard options. Please contact us for different color options. Dimensions: Inner: 12,5 mm Outside : 20 mm Thickness: 3,5 mm