These cameras takes 4,5V battery what is long time ago not in production.To find any is not an easy job. This article will guide throw how you can make an own replacement solution.
So the first step is to find a tube that fits the battery holder on the Praktica.
Once the marker body empty and (moreless) clean, it has to be cut to the right size:
Three button 1,5 volt batteries, add up 4,5 volt.
Since the internal diameter of the marker was too wide for the batteries, I added a filling cylinder of paper. Also I cut a piece of spring to fill in the remaing space:
so here we have the adapter with a finished spring
Now time to put in the batteries:
Special thanks to Jesito he made this manual.