Wide Range of Use - These book rings could be used for creating notebooks and sketchbooks. The circular metal rings could also fit for keeping keys. The openable rings can also be used as curtain rings. Polished Finished - The brushed nickel book rings are made of high-quality metal. It is strong and durable, and won’t rust easily. Easy to Use - The loose leaf rings are convenient to use, just pull to open and squeeze to close. And it is easy to open and close. Large Binder Rings - This large loose-leaf ring has an inner diameter is 63mm (2.48 inch), outer diameter is 70mm (2.76 inch), thickness of 4mm/0.16inch, and 20 pieces can meet most of our daily needs. Please ensure that the product size is suitable for your needs before buying.