Filling Mechanism
Besides the obvious use of writing, the most exciting aspect of the Vac700R is the filling mechanism. The one-stroke plunger mechanism draws over 2ml of ink with ease. For a cleaner, quicker fill, TWSBI designed the Vac 20 ink bottle to work specifically with the Vac700R and Vac Mini fountain pen.
If you're familiar with the Pilot Custom 823 or with Opus 88 eyedropper fill pens, the Vac700R's shut-off valve works in the same way. When you have the barrel end cap completely closed, the shut-off valve will prevent the ink inside the barrel from accessing the feed. This is to protect from accidental ink burping while traveling. Unscrew the end cap for longer writing sessions to keep the ink, and creativity, flowing.