Kugel Extra Fine— whatever that means. When these nibs are ground to a point that is thinner than a F, differences between them becomes marginal. You will not be able to distinguish whether they are a Kugel nib or a Oblique nib by feel, because they all feel the same on paper, that the point is so fine.
At least for me, I can’t tell whether I am using an EF or KEF as the point are so damn thin. With these points you have use a light hand to enjoy them, and if you are ham fisted, don’t bother with these “EF” type of nibs, they’re a scratch-a-lot!
I have bought and owned my shares of Pelikan 400s, and at the end I found their EF nibs just doesn’t suit my taste. I do fond their F nibs, though. Lovely!