This rollerball pen can be used with a European type fountain pen ink cartridge. The feature is that the ball portion of the pen tip rotates so you can write smoothly. Always carry around and enjoy the taste of writing like a fountain pen. A Cartridge Black includedPackage / PET case, H 1.5" x W 4.4" x D 0.75"BRASS ROLLERBALL PEN / D 0.5" x H 4"Nib : 0.5MMMADE IN JAPANNo.36727006 There’s something extraordinary about brass-based products. The appearance that resembles warmth, and the change in color and texture through long time use enriches one’s affection towards the product. Brass is an alloy consisting of bronze and zinc, and has been used in architectures, furniture, and arts and crafts. Through its use, the surface starts to oxidize, and this deepens the color and adds taste to the material itself. In order to allow people to use the products with care for a long period of time, we made the shape of the products simple and made use of the properties of the material.