Wide range of uses for loose-leaf, flash cards, memo filing, key rings and sample holderClosed tight, not scattered after collapse, keep your desk always organizedThe steel metal round rings can be split into two halves and is by a metal swivel which is located at the center of the ringYou can 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 , 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:Line thickness 2mm, inner diameter 15mm, outer diameter 19mmMaterial:ironcolour:SilverPackage Contents:100 * Binder RingsOnly the above package content, other products are not included.Note: Light and different displays may cause the color of the item in the picture a little different from the real thing. The measurement allowed error is +/- 1-3cm.