A hole punch is a helpful desktop tool which expands your filing capacities greatly. A typical hole punch has a lever which pushes bladed cylinders through multiple sheets of paper. 

Standard hole punches have 80mm of space between the holes, and a hole size of 6mm. This is known as the ISO 838 template. Standard 2 hole punches are the most popular punch purchased in the UK. 

Most 2 hole punches come with a paper guide. This allows you to adjust the punch for repeated punching of paper according to its size. The guides normally have pre-set positions for the standard sizes A4, A5,A6, American Quarto, and foolscap. If necessary, you can set the guide to a custom position between the parameters of the standard set sizes.