Feature: 1. Paper Capacity: These double loop wire binding spine can accommodate up to 180 sheets of A4 paper, a total of 70g, meeting your needs. 2. Metal Inner Wire: The interior of the binding loop is iron wire, which is sturdy and durable, allowing you to easily fix paper and store it for a long time. 3. Nylon Coating: The exterior is nylon coating, with good surface gloss, corrosion resistance, wear resistance, and long service life. 4. Perfect Size: Each binding spine has a diameter of 3/4in and a thickness of 0.8mm. Each spine has a pitch of 3:1 and 34 double loops, which supports 360 degree rotation. 5. Binding Lines: These double loop binding wires can be used to bind important documents, files, or reports for upcoming presentations or projects. Specification: Item Type: Double Loop Wire Binding Spine Binding Diameter: Approx. 19mm / 0.75in Binding Capacity: 180 sheets. A4, 70g. Loop: 34 Loop Pitch: 3:1. Package List: 50 x Double Loop Wire Binding Spine