Change up your writing experience with a replacement nib. This German-made, stainless steel, Jowo nib and feed assembly can easily replace your Retro 51 fountain pen nib (made in 2018 and onward). The no. 6 size nib is adaptable to many other brands of fountain pens as well, including Edison, Franklin-Christoph, Diplomat, Montegrappa, and more! What's the point? Being able to change your nib from a broad to an extra fine makes a great deal when you're finely printing your study notes or meeting agendas in your notebook.