The fountain pen has a piston converter with a viewing window so you can see not only the level but also the color of the ink.

The roller is even more minimalist: The capless refill is clamped in a holder, remains visible and is supported by a pressure mechanism.

All pens are made in Germany and are equipped with an "anti-roll" function, a small metal ball on the back of the cap.

The term Calamus refers to the historical writing instrument of the Romans - a pointed reed that was dipped in ink.