0.9 mm pencil lead refills for the Autopoint Twinpoint mechanical pencil. The tube contains 12 red leads of B hardness. To fit in the Twinpoint pencils, the lead length is 1.375 inches, which is shorter than standard leads.
You'll need this quickly, since Autopoints have tiny lead capacity, can only
hold one lead, and, for notetaking, will run out after annotating a few hundred
pages. It's not immediately apparent but to replace the lead you'll need to
unscrew the thread that advances the lead within the Autopoint cap.
In my experience the red Autopoint lead is more brittle than the blue, but
they're still very useful.