Features 1. SPOOL SPECIFICATIONS: These binding bobbins have a diameter of 25.4mm (1 inch) and are perfect for adding and removing paper, with binding capacity of 215 sheets. 2. 360 DEGREE ROTATION - These spiral binding spines allow 360 degree page rotation and the binding elements can be laid flat to ensure comfortable reading. 3. 4:1 STANDARD STEP - These plastic spiral binding bobbins have a 4:1 pitch, which is compatible with any binding machine that punches 4 holes per inch. 4. Applicable paper: these 48 loops binding bobbins are suitable for letter size paper (8.5 x 11 inches) and the length can be cut according to your needs. 5. WIDE APPLICATION - Includes 35-piece binding spines, perfect for engineering documents, business projects, office documents and college presentations. Specification: Item Type: Spiral Binding Coil Binding diameter: 25.4 mm / 1 inch. Binding capacity: 215 sheets (A4, 70g) Number of loops: 48 loops Step:4:1 How to use: Take out the product, install it and use it. Packing List: 35 x Spiral Binding Coils Package List 35 x Spiral Binding Coils