Item Type: Plastic Spiral Binding CoilsInner Diameter: Approx. 19mm / 0.75inType: Stationery accessories binding consumables .wang-edit-text{ font-family:'Arial' !important; } .wang-edit-text table { border-top: 1px solid #000; border-left: 1px solid #000; } .wang-edit-text table td, .wang-edit-text table th { border-bottom: 1px solid #000; border-right: 1px solid #000; padding: 3px 5px; } .wang-edit-text table th { text-align: center; } 1DURABLE WITH LONG LIFE: Durable and sturdy plastic binding spirals allow you to easily compile paper and store for long periods of time 2CONVENIENT BINDING METHOD: Can be manually bound by punching suitable holes, which can be easily operated by any office, student party, and individual 3GOOD GLOSS WITHOUT BREAKAGE: Possess good surface gloss, strong adhesion, wear resistance, rust resistance, aging resistance, not easy to break and fade, smooth page turning, can be used repeatedly 419MM INNER DIAMETER: Stationery accessories binding consumables, inner diameter for 19mm, suitable for students and teachers 520PCS IN TOTAL: The package contain a total of 20pcs binding spirals, enough for you to replace and use, very convenient20x Plastic Spiral Binding Coils