Rotring Rapidograph is the ultimate technical pen with pre-filled, disposable capillary cartridge - a completely new concept in technical pens! Virtually no maintenance needed..This new drawing pen that receives a clean, fresh breathing system with each new pre-filled cartridge. The ink reservoir and breathing system are in one piece. No leaking...The Rotring pen is the first drawing pen with a double-rotating breathing helix in the ink cartridge. As the diagram shows, the breathing helix of the new capillary system runs in one direction on the inside of the capillary cartridge and continues in the opposite direction on the outside. Instant ink flow... The technical design of the Rotring Rapidograph pen and specially formulated ink in the prefilled cartridge prevent ink from drying in the system. Available in 10 line widths from which to choose: 0.13, 0.18, 0.25, 0.30, 0.35, 0.50, 0.70, 1.00, 1.40 and 2.0. A practically maintenance-free color-coded drawing pen for drawing and lettering in accordance with ISO standards. Suitable for microfilm work. Fully equipped with capillary cartridge, drawing point, holder, cap with double seal and clip.