What kind of pen is this?

Glass pen (Japanese: ガラスペンンン), also known as glass pen, based on the principle of capillary action, stores ink in several grooves on the nib, and these grooves can also guide the ink to the nib, thus forming a special ink supply device. When writing, the amount of ink and the thickness of handwriting lines are determined by the depth, width and writing angle of the ink storage tank on the pen head. The main types of ink storage tanks are linear and spiral. The change of lines can not only provide visual beauty, but also provide more ink storage space.

There are two main types of glass pen: glass fountain pens and glass dip pens.