These Rotring Short Ink Cartridges in Medium Black are suitable for refilling any pen from Rotring's large ArtPen range. Elegant Rotring ArtPens turn even the simplest piece of writing into a small work of art. They're refillable fountain pens with high-quality stainless steel nibs, and are ergonomically designed to make them extremely comfortable to use. Of course they're ideal for adding a touch of style and personality to all your everyday writing, but they're also perfect for technical drawing and design.