Durable Zinc Alloy: The spring o rings are made from sturdy zinc alloy, which is shiny, and not easy to fade, anti-rust, anti-corrosion, and durable for long-lasting use, ensuring reliability and durability. Spring Snap Design: The O rings have a built-in spring structure that provides a secure closure for fastening needs, allowing the ring to automatically maintain a fastened state when closed, and is convenient and quick to open and close, a labor-saving operation, and can be used repeatedly. Easy Attachment: Just pressing the spring hook can quickly open the connection, and it will automatically close when released, ensuring the stability of the connection. Wide Range of Uses: The spring keyring buckles are great for use with hand DIY accessories, handbags, purses, bags, shoulder bags, wallets, and more, and can also be used for crafting, organizing, and securing items in various settings. Material: Zinc Alloy Color: Black Inner Diameter: 13 mm / 0.5 inch Outer Diameter: 20 mm / 0.8 inch Thickness: 3.5 mm / 0.14 inch Package Included: 30 pcs x Spring O Rings