This is a simple clamper to fix a high voltage step up converter I use to power vacuum tube circuits.
The model is "70W DC-DC Step-Up Power Supply Module I/P 9-24V O/P 200-450V Adjustable
Thi step up is very handy to test circuit operating point before the final draft.
You need to print two for this model.

You can see them in action in my site:
http://agalavotti.altervista.org/