Check the listing for details. 8mm(5/16") Spiral Binding Coils, 100 Pcs Spirals 40 Sheet Capacity, Black. Condition: New. Listed at 24.90 USD. These plastic spiral binding coils are suitable for various office occasions and provide great convenience for file storage, file binding, paper collection, etc.It is a portable product for office and study.SpecificationInner diameter: 8mm/0.32 inch; Length: 31cm/12.2 inch;Coil spacing: 4:1;Number of binding pages: 40;Material: plastic;Color: Black;Packing List: 100 Pcs Plastic Spiral Binding CoilsAdvantageThe spiral binding coils are made of long-lasting, strong plastic to ensure long-term productivity for all your binding projects, allowing you to easily bind papers and preserve them for a long time.InstructionSpiral binding coils have a 4:1 pitch, making them suitable for any binding machine that punches 4 holes per inch.Binding spirals provide a 360-degree page-turning rotation capability for easier reading.