1. The loose-leaf rings are easy to use, you just need to pull them to open and squeeze them to close. 2. The book binders lock securely, with the multi-layer nickel-plated material, will not crack, break or split easily. 3. This type of binding rings are suitable for loose-leaf, memo filing, key rings, scrapbooks, sample holders and so on. 4. The book rings are approximately 25 mm in inner diameter and 30 mm in outer diameter, small size, can meet your editing needs for small items. 5. Loose-leaf rings are made of nickel-plated metal, with 25 mm inner diameter, very strong and durable, allows you to use them for a long time. The loose-leaf binders are small parts, not suitable for children under 3 years old. Use them under adult supervision, do not leave your children alone to use the book rings. Features: The lead binders can scrapbook files, DIY albums etc. You can use the loose-leaf binding provided you switch hard (strength) to open. These loose-leaf binding rings are very suitable for memo filing, key rings, scrapbooks and so on. The binders are easy to use, you just need to pull them to open and squeeze them to close. Specifications: Material: Iron Color: Nickel-plated Metal: Electroplating Inner diameter: 25 mm (1.0 inch) Package included: 20 pieces hinged snap rings