What is it? This is not a hole puncher, but more like a hole maker. You'll need this in case of a thread binding, to help your needle to pass through the sheets correctly (the sheets need to be alligned - if that's what you want) In this case, a knife would not work. What about a needle? That's already what will pass through the holes. You can also use a needle that is a tiny bigger than the one you'll use for binding later. Yes, it does hurt a bit when the paper is not very thin. A solution is creating your own tool, by attaching or glueing a needle inside anything that you can hold with one hand.