Hiace Neo Clear Fountain Pen

The pen body, as well as the tip and core, are transparent, so you can see the ink flowing.
You can also see the remaining ink level, so you don't have to worry about running out of ink suddenly.
Even those who are new to fountain pens can use it with ease.
Since it has the same functions as a genuine fountain pen, in addition to cartridge ink, you can also easily use bottled ink by attaching an ink absorber converter (sold separately).
You can also customize it to your liking with a variety of color inks.