Hi there. I saw this with my own eyes as I worked nearby. Thanks

It’s been over a year again since I was there so it might have moved. Feel free to change it.

Hello. The place is called steak house Jena and is a very nice place. I had a very nice and good meal there. I can recommend it. Thanks, Marc

It is a IEC 60309 connector. See https://en.wikipedia.org/wiki/IEC_60309

OK