Superior Quality : Our 11pcs metal binding discs are made of high quality aluminium alloy, which ensures the product is sturdy and durable, keeping your documents securely bound and preventing them from falling apart.Size Reference : Alloy binding discs are 18mm/0.7 inch in diameter, 5mm/0.2 inch thick, 15mm/0.59 inch inside diameter, suitable for most beginner, intermediate or envelope size notebooks.Easy to Use : Our metal binding discs are designed with ease of use in mind, allowing you to bind documents quickly and efficiently. The discs are easy to open and close, and you can add or remove pages as needed.Cost Effective : Our metal binding discs are a cost-effective and reusable alternative to expensive binding machines or flimsy plastic discs for document organisation.Wide Application : Perfect for students, professionals or individuals to organise their documents, can be a great gift for birthdays, holidays or other special occasions.