Its great performance is due to the pencil's innovative Orenz mechanism. The guide pipe protects the entire length of the lead, and you write without extending the lead out of the guide pipe, which glides right along the surface of the paper. Since it has rounded edges, the guide pipe doesn't catch on the paper or scratch it. As you write, the guide pipe gets shorter. When you need more lead, just click the top button as you would with any other mechanical pencil. The guide pipe will extend again, along with the lead inside.