Designed for use on a variety of paper surfaces. The pen is refilled with cartridges, which uses Rotrings unique capillary system. Set consists of 3 radidograph technical pens 0.25, 0.35 & 0.5mm. 1 rotring T mechanical pencil 0.50mm, 12 hi-polymer HB leads, 1 B20 eraser, 3 pen stands, 3 ink cartridges, 1 compass attachment.