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 convenient