This is not a pen, but a design object. (Note from TYPE: It's also a pen).
The inscription "Drehgriffel" appears on its hexagonal body. A derivation from Sütterlin, a source script for learning cursive script developed in Germany in the 1920s. This and a narrowly tapered tip, which, like the rotary knob, is contrasting in colour, distinguish the Drehgriffel.
The Drehgriffel Nr. 1 is a ballpoint pen made of precision milled aluminium and brass, lacquered and sealed. It contains a spring-loaded twist mechanism. To change the refill, simply unscrew the twist head.
Details:
• Ballpoint pen made from precision-milled aluminum and brass
• Ceramic ball bearing
• Stroke size 0.5 mm
• Black ink
Refills available here