Koh-I-Noor Rapidograph technical pens are made of impact and chemical-resistant components for universal use with drawing and specialty inks. Each cap has a pocket clip and an air-tight double-seal liner. They feature long streamlined holders for good balance. Koh-I-Noor Rapidograph pens are available in a variety of line widths. The self-polishing, hard-chromed stainless steel points are for use on paper and drafting cloth.