belongs to the more technically complex filling systems.
The cap (3) is unscrewed in a vertical position, the barrel then filled by means of a pipette (4) and then re-capped.
For writing the pen must be opened in a vertical position, the nib (1) is propelled upwards by the twist mechanism (2), that is operated by turning the knob at the end of the barrel (5) clockwise and thus seals it from the inside. The pen is then ready for use.
After use the pen has to be held upright again, the nib retracted by turning the knob anticlockwise and the barrel then capped with the cap, which makes it airtight. As the nib inside is surrounded by ink it is always ready to write. Inside the cap of most MONTBLANC safeties is a silver pin that fits into a groove in the feed, thus protecting the nib from being accidentally damaged by turning the knob if the pen is capped.