Spring O-Rings, also called oval spring 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 zamak metal and are professional quality durable and very easy to apply. Special coating has been applied to make shiny, smooth metal rings. You can view our other buckle and ring accessories here. Standard colors are presented in options. Please contact us for different color options. Dimensions: Inner: 12mm x 22.7mm Outside : 20mm x 30mm Thickness: 4mm