日本立川鋼筆咀通用筆桿附保護蓋TACHIKAWA Universal Comic Pen Holder - comfort handle with cap
This is a pen body only. A variety of nib styles are available separately. This holder is compatible with both regular and round nibs. The holder features special double rubber rings at the tip; the inner ring can take smaller round nibs and the larger ring can take regular nibs. The rubber grabs the nibs tightly, preventing shifting when drawing.
Comic nibs are famous for producing strong and crisp lines that are difficult to duplicate with pens and brushes. They are great for creating detail in drawings.