To my knowledge, the w222 doesn't use a physical SIM card, in the Hermes module, so this must be something different.

I have a SIM card tray module inside the glove box compartment. However, I was not able to identify what it is, or what it is used for. I should also mention that there is 4G internet connection in the car, and Mercedes ME functions correctly, without any SIM cards inserted.

A google search showed no results. In EPC I could not find a part that would match.

It does seem OEM looking, but just weird that I don't find anything about it.

When sitting in the back, and trying to make a phone call, using the remote and the Comand screen, I get a message saying that "business telephony is not activated".

The car in question is a w222 Facelift, with the Executive package (2 back-seats, no foldable tables).