These wires are suitable for use with a wire binder of 3:1 pitch - that is three holes to the inch. They are for binding A4 books. Currently, these A4 3:1 Rexel Wire Binding Strips, 12.5mm Black pack of 100, are on sale, elsewhere on the web, for £39.05 + £8.50 delivery + £9.51 VAT = £57.06. Buy from me for only £20 FOR 500. They are surplus to requirements and I need the space. Therefore, I am charging just £20 for 500 WIRES (5 BOXES OF 100). Collection from Weston-super-Mare.