Wide range of uses for loose-leaf, flash cards, memo filing, key rings and sample holder Closed , not scattered after collapse, keep your desk always organized The steel metal round rings can be split into two halves and is by a metal swivel rivet which is located at the of the ring You can easily link numerous loose-leaf booklets, paper cards, name tags, instruction guides or plastic plates How to use: The loose book ring has 2 parts and is linked by a swivel rivet, very easy to operate, you can pull the opening to open and squeeze to . Notes: Do not leave your children using the book rings alone, adult is required. size: thickness 2mm, inner diameter 15mm, outer diameter 19mm Material:iron colour:Silver Package Contents: 100 * Rings Only the above package content, other are not included. Note: Light and different displays may cause the color of the item in the a little different from the real thing. The measurement allowed error is +/- 1-3cm.