Metal Black 1.2 Inches Key Ring Chain Split Ring (Pack of 50) Size: 30mm /1.2 inch (outside diameters) * 25mm/1 inch (inside diameters) Great for connecting clasps, charms, links and other jewelry Lightweight and sturdy High-security connection and attachment for keys and other important items The spring tension is firm enough that keys don't slip out and also soft enough to make putting items on reasonably easy.