Is a vintage French nib.
This vintage Gilbert & Blanzy-Poure Départementale Cementée N°2552 dip nib is a long-ago favorite from France. Ink flow is easy, the nibs last a long time, and it has great flex. It can produce very, very fine hairlines followed by thick swells, and is great for general letter-writing, as well as fancy Spencierian script, if that is your thing. A great addition to any beginner’s stash.