Fuliko PROC1530BK Click Binding Spines, 3:1 Ratio, Capacity for 120 Sheets, 3/5" Diameter, , 30 per Box

Broad Compatibility: Accommodates both A4 (8.3" x 11.7") and U.S. letter size (8.5" x 11") papers. For U.S. letter size, minor adjustments with scissors may needed. Substantial Binding Ability: Secures Up to 120 Sheets (80g/20lb Paper), for Documents, Slideshows, and Guides. Convenient Functionality: Allows for Easy Page Insertion or Removal; with 3:1 Pitch Binding Devices. Hole Centers are 8.4mm Apart. Monochrome Package: Contains 30 Binding Spines Binding Edges: Edge Size Influences Sheet Quantity; 3mm Edge for 10-120 Sheets (80g/20lb Paper) and 6mm Edge for Up to 80 Sheets (80g/20lb Paper).