Aside from interesting ephemera and useful tools like the Signagraph, Waterman created some other handy items. The Waterman 20S was a prohibition era flask from the 1920s. It was supposed to look exactly like a Safety Pen, but was an innovative and sneaky rubber flask! Considering the average size of other vintage pens, the Waterman 20S was comparatively huge.
Below, the Waterman 20S next to a Waterman 420 and Waterman 20.