The 21 hole comb binding ring fits A4 sized paper (8.3 x 11.7inches), which is not a standard U.S letter paper size (8.5 x 11inches). Binding letter size need to use the scissor to cut off two rings. The picture shows the difference between A4 and letter size paper.
Sheet Capacity: 90; Spine Diameter: 1/2"; Number of Rings: 21, length: 11.8inches/ 30cm.
Get a professional edge! Quantity/Unit - 100/Box
Available in a variety of sizes and colors to bind 2-90 page documents. 3mm margin for binding 2-90 sheets ( max. binding thickness: 9.5mm/0.37in), 6mm margin for binding 60 sheets ( max. binding thickness: 8mm/0.31in).
Designed for a variety binding of paper size. Perfect for internal reports and functional documents.