Features Durable PP Material The spine is made of excellent PP plastic, is not harmless, has good wear and rosiness, anti-aging, sturdy and durable. 22mm 30 Holes This is a 30 hole loose-leaf binding strip with an inner diameter of 22mm, which can hold multiple sheets at the same time. Wide Range of Use The binding strip can be manually tied by punching suitable holes, which can be easily operated by any office staff or student. Good Performance The surface of the binding strip is shiny and has strong adhesion, not easy to break, flips smoothly and can be used repeatedly. 10 PCS SET The set contains 10 pieces of these spines, so you can easily store paper and use for a longer period of time. Specification: Item Type:Loose Leaf Binding Combs Material: polypropylene. Inner diameter: approx. 22 mm / 0.9 inches. Type: Stationery Accessory, Binding Accessories Package list: 10 x loose leaf binding combs. Package List 10 x Loose Leaf Binding Spine