KURETAKE-Zig: Cocoiro Letter Pen: Ink Refill. The flexible semi-hard tip of the Cocoiro Letter Pen is what sets it apart from regular pens. You can create various styles and widths of lettering depending on the pressure and speed of your writing. And with the fun system of interchangeable pen bodies and refills you can create your own personal pen that is unique to your individual style! Both the bodies and the inks come in several colors that can be mixed- and-matched so go ahead and create one for home and one for work; or make a whole set for use with all of your paper crafting projects! This package contains one black ink refill with a brush nib. Pen body is not included; all bodies are sold separately. Conforms to ASTM D-4236. Imported.