Pelikan M600 Blue Demonstrator, M620 18K Medium, inked with Franklin-Christoph Noir et Bleu
This M600 Blue Demonstrator was once broken check this post for the full story.
The nib says M for medium but this older style (early 2000s) 18K nib writes like a modern fine.
Franklin-Christoph is one of my favourite manufacturers. While I am unlikely ever to own any of their pens I do buy all the ink releases and many of their pen cases. Franklin-Christoph sell their ink in a sensibly tall, wide mouthed bottle.
Noir et Bleu is french for black and blue. This ink leans more black than blue being very dark. No shading or sheen to be seen but I do like this ink. It is a serious ink for the office.