I'd be interested in the model if you have the opportunity to check! Thank you.
https://www.gira.com/en/gebaeudetechnik/systeme/knx-eib_syst...
You can see what one looks like in place here in the middle of this picture. I use black ones for my wood ceilings.
https://i.imgur.com/pTCOKJx.png
On the left hand side is one of the air quality sensors.