Rotring Rapidograph Technical Drawing Pen Junior Set, 3 Pens with Line Widths of 0.25mm to 0.5mm, Brown (S0699480)

The rapidograph uses rotring's unique capillary cartridge. The pressure-equalization system, including ink helix is part of the ink cartridge which ensures that every time you change the cartridge, you get a clean new ink helix. This means that you never need to clean the ink helix and top reliability is guaranteed.