Spiral Binding Machines use a Coil of Plastic or Metal which is inserted into pre-punched hole already cut into a document.

2:1 Binding Wires

2:1 Binding Wires are the perfect for use with Multifunction and Wire Binding Machines and feature 2 holes per inch. This usually means 16 loops for A5 wires and 23 loops for A4 wires.