Enameled copper provides some of the brightest and most colorful rings you will find. They are made by coating the wire with a durable plastic enamel that should not peel or flake. Rings come in a wide variety of sizes and colors. If you don't see what you are looking for, email or call us directly. Our jump rings follow the American Wire Gauge (AWG), also known as Brown and Sharpe (B&S). All sizes listed are inside diameter (I.D.), measured in millimeters which corresponds to the size of the mandrel onto which the wire is wound. Use these I.D.'s as a guide not an absolute. All rings are tumble polished for a bright shiny beautiful jump ring. Occasionally you might get a misshapen ring or an end cut half ring. To account for this, we put extra rings in every bag. Approximately 130 pieces per package.