Check the listing for details. 50 Pcs 6mm Plastic Binding Combs 20 Sheet Capacity 21 Rings White. Condition: New. Listed at 19.47 USD. Description:Specification: Inner diameter: 6mm (1/4 Inch); Length: 300mm/11.8 Inch; Number of binding pages: 20; Material: plastic; Color: White; Packing List: 50 Pcs Plastic Binding Comb SpinesAdvantage: The binding comb spines 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.Instruction: These binding comb spines are designed in 21 rings, making them suitable for any 21-hole rubber ring binding machine. Binding spirals provide a 360-degree page-turning rotation capability for easier reading.Application: These plastic binding comb spines 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.