The Pentel Orenz is a Mechanical Pencil with an anti-breaking lead system.
Click once to extend the anti-lead breaking sleeve along with the lead inside. The lead does not need to extend past the sleeve. The guide pipe protects the entire length of the lead, which enables you to write without extending the lead out of the guide pipe. Since the pipe has rounded edges, it will not scratch the paper. The sleeve will retract as the lead is used. Once the sleeve stops retracting, click once to start writing again.
This mechanical pencil uses 0.5mm leads.