Every geek needs to create something unique in the course of his life, namely his own watch. Johannes wanted to change the way the time is displayed on a custom wristwatch. LED’s were too common, and mechanical indicators with small engines were too expensive, but Johannes though that Nixie tubes would be the right option.
In an evacuated glass bulb filaments are attached in the form of a 7-segment display. It is a multi-filament lamp and not to an electron tube, as there is no electron flow from a cathode to an anode by a gas or a vacuum. They were called Numitron.
The video below demonstrates how Johannes creates the Numitron Geekwatch.