21-hole binding rings are perfect for A4 size paper. Available in four white sizes: 6mm, 8mm, 10mm, and 12mm. Binding capacity: 6mm ring - 20 sheets, 8mm ring - 40 sheets, 10mm ring - 55 sheets, 12mm ring - 90 sheets. Made of high-quality PVC resin material, the binding rings will not easily break, come off, or discolor, and can be used repeatedly. The material is soft and easy to cut, so you can cut it with scissors to sizes like A5 and B5 according to your needs. 4457