Pentel Orenz Lead Supporting Mechanical Pencil Blue // 0.2mm
This is a 0.2mm mechanical pencil with a clever lead-support design.
The design uses a sliding tube that slowly retracts into the tip of the pencil as you're writing. As you write, the lead slowly wears down, and this tube follows the lead all the way. A single click and the tube is advanced, and you're ready to start writing again.
The Orenz can also write at almost any angle without issue as the metal tube doesn't snag the paper.