Fellowes 32mm 5:1 pitch metal binding spirals in black (50 units) 5111501 are designed to support high-density reports and books. This box of 50 units, 32mm diameter, in black metal with a 5:1 pitch, can bind up to 290 A4 sheets in a compact and manageable format. The black finish ensures a clean and very professional spine. Recommended for public bodies, copy centers, and central company archives.