100 Pack: 100 Pack Binding Combs Included, ensures long-term productivity for all of your binding projects, allow you to bind paper sheets with ease and store for a long time. 20 Sheet Capacity: Plastic Binding Combs measure 6mm (1/4") in diameter, perfect to add and subtract paper sheets, can hold up to 20 sheets. Easy to Use: The plastic binding combs are compatible with any standard 21-ring comb-binding system, Perfect for internal reports and functional documents Wide Application: The binding combs can be used in business project, office documents, family plan, presentations,restaurant menus and more. A4 Size Compatibility: This black 21-ring binding comb is specifically designed for A4 paper (210mm x 297mm). For other paper sizes, the length can be easily trimmed with scissors.