Fellowes 18mm 5:1 pitch metal binding spirals in black (100 units) 5110701 ensure a solid and elegant structure for documents up to 150 A4 sheets. This pack contains 100 units of 18mm flexible black metal with a 5:1 pitch, preventing pages from coming loose with frequent use. The black color is universal and matches any cover style. Suitable for institutional reports, procedure manuals, and sales catalogs.