Krieg wrote: ↑Sat May 04, 2024 9:43 am
Indeed protection for children, you didn’t have to remove it, you put the two prongs of the plug in the two holes of the protector and then rotate the plug until you find the socket holes and the plug goes in. Normally you have to rotate 90 degrees.
The problem is: The picture as posted by the OP only shows one hole...
The OP has found this in a socket:

- Steckdose1.jpg (31.64 KiB) Viewed 2264 times
That one hole is there to also make it compatible with the French style of sockets where PE is not the two clamps on the side but is a pin protruding out of the socket ("one size fits all"):

- Steckdose2.jpg (31.95 KiB) Viewed 2264 times
The "protection device(s)" as mentioned by Krieg looks different:

- Steckdose3jpg.jpg (222.15 KiB) Viewed 2264 times