This is a pencil with a replaceable and mechanically extendable core.
If you've ever been frustrated to find your writing with a mechanical pencil looks uneven, the Kuru Toga is the pencil for you! As many mechanical pencil users have noticed, the lead typically wears down on only one side, forcing you to write using the large flat, blunt edge of the lead, or the super pointy tip. Mitsubishi's fantastic answer to this problem is the Kuru Toga - a mechanical pencil which automatically rotates the lead as you write, so it never wears down unevenly! Every time you press down and lift up the lead of the pencil whilst writing, the lead is automatically rotated. You won't even notice it happening, but your writing will be all the more beautiful for it!
This Kuru Toga comes in blue. It takes 0.5mm lead.