GBC ProClick Easy-Editing Binding Spines, 0.31-Inch Spine Diameter, Black, 45 Sheet Capacity, 100 Pieces Per Box (2514700) PROFESSIONAL PROCLICK  Choose the convenience of ProClick. Dependable black binding allows you to easily open and add or remove pages without a machine. Ideal for use in busy corporate offices. 45-SHEET CAPACITY  With a 45-sheet capacity, the 0.31" diameter ProClick spine is an excellent choice for most projects. Versatile enough for use in everything from presentations to scripts. EASILY EDITABLE  Enjoy the flexibility of proprietary ProClick technology. The sturdy binding spine simply zips open and closed. Use your finger or a pen to open it - no need for a machine. CONVENIENTLY READABLE  Sturdy ProClick binding allows 360 degree page-turning capability for easy reading of bound documents. EXCLUSIVE COMPATIBILITY  Proprietary ProClick technology is exclusively compatible with GBC ProClick binding machines (sold separately). 100 PER BOX  A box of 100 spines ensures long-term productivity for all of your binding projects.