Feature:1. DIY: New style mushroom hole binding ring, which can be freely arranged, increased or decreased to bind the inner pages.2. Small Disc: It is a small disc with raised edges that can rotate the book 360 degrees.3. Arbitrary Combination: The paper with mushroom holes can be combined at will, the inner page can be turned over, and can be increased or decreased at will.4. Mushroom Hole: Through the mushroom hole, the inner pages can be turned into different inner pages, which can be matched according to preference. It is a good choice for daily notepad binding.5. Material: The color expansion tray is made of high quality plastic, which is safe and non toxic, with a glossy surface to ensure no page jams when turning pages; small and lightweight, easy to store, use or carry on business trips.Specification:Item Type: Binding RingsMaterial: PlasticDiameter: Approx.10mm / 0.4inBinding Pages: 30 Sheets.Package List:12 x Binding Rings