Features1For Your Paper: Designed to have 13mm inner diameter, the spiral binding coil enables smoother page turning for reading and writing.2Better Binding: Easy to install and remove, you can also cut the binding comb into your preferred length for your needs of storage.3Large Capacity: Able to clip a large amount of sheets, the binding spine suits ly for office, classroom, library and so on.4Great Material: Made of plastic material with pretty colour, not easy to deform and very durable with corrosion and long use.520Pcs in Total: There are 20pcs spiral binding coil in the set, and the large quantity will simplify the replacement of damaged ones.SpecificationItem Type: Spiral Binding CoilInner Diameter: Approx. 13mm / 0.51inType: Stationery accessories binding consumables.Package List20 xSpiral Binding Coil