GBC Binding Spines/Spirals/Coils, 1/2" Diameter, 85 Sheet Capacity, ZipBind, Black, 50 Pack (15006) ZIP IT WITH ZIPBIND  Black ZipBind spines provide a sturdy, convenient option for everyday binding. Professional, sleek-looking spines are machine-compatible, but are also editable by hand. 85-SHEET BINDING CAPACITY  Black binding spines are the perfect choice for medium-sized projects. With a 1/2 diameter, they securely hold 85 pages, allowing plenty of space for your work. EASILY EDITABLE  Convenient ZipBind spines are easily editable. Simply open the binding, using a pen or the specialized tool (included), to edit or rearrange the contents. CONVENIENTLY COMPATIBLE  Spines are compatible with CombBind punched documents and binding machines (sold separately). Easy to use with CombBind machines. 50 SPINES PER PACK  With 50 spines per pack, these handy spines are sure to help support your busy projects, assisting with long-term binding productivity.