Fellowes 30mm 5:1 pitch metal binding spirals in black (50 units) 5111401 enable the grouping of massive volumes of A4 documentation. With a 30mm diameter and 5:1 pitch in black coated metal, this set of 50 units allows you to bind up to 270 sheets with complete ease. The continuous spiral structure ensures that the pages do not come loose when flipping. Suitable for continuing education manuals, general catalogs and technical reports.