Fellowes 5:1 pitch 24mm black metal binding spirals (100 units) 5111001 guarantee robust support for binding up to 210 A4 sheets. Made of black metal wire with a 5:1 pitch and a diameter of 24 mm, these 100 spirals provide perfect page retention without sacrificing flexibility. The sober black tone adapts to any professional or academic environment. Essential for archiving large projects and extensive files.