Item Type: Binding Spines Inner Diameter: Approx. 13mm / 0.51in Type: Stationery accessories binding consumables 1DURABLE WITH LONG LIFE: Durable and sturdy plastic binding spines allow you to easily compile paper and store for long periods of time 2BINDING METHOD: Can be manually bound by punching suitable holes, which can be easily operated by any office, student party, and individual 3GOOD GLOSS AND NO 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 413MM INNER DIAMETER: Stationery accessories binding consumables, inner diameter for 13mm, suitable for students and teachers 510PCS IN TOTAL: The package contain a total of 10pcs binding spines, enough for you to replace and use, very convenient10 x Binding Spines