By far my worst purchase ever. I got the pack of 50 (K86/50) and ended up throwing them away.. The pen writes 2-3 letters and then stops... repeat. I always stored them with the tip down so that the ink wouldn't move away from the tip, but no matter how many I tried, they all had exactly the same problem. Prefer BiC, at least they will write until they run out.

Out of the 4 I have bought, 3 stopped working, meaning they had ink but stopped writing. The one that worked properly ran out in a week. It smudged the paper.

Compared to the equivalent BIC:
it has a softer writing, good grip
the ink runs out faster
when writing, it leaves a lot of ink on the tip and dirties the paper

The pen is simply perfect. One of the best pens I have ever used. Its grip is very comfortable and its quality is unique. The ink is exceptional.

Triangular grip, very thick suitable for large palms-fingers, comfortable smooth writing, I didn't like that the ink tube can be heard a little when I write and that the cap doesn't secure tightly - it attaches to the top of the pen, resulting in me searching for it.