Has anyone ever 'time measured the dimensions?

Me, yes. Not 3.2cm thick, but 3.9 cm. Does not appear much more, but I wanted / want you so something subtle and they are due to the thickness then never more. So be careful before ordering and pay attention not only to the diameter. A larger, but shallower smoke detector probably does not stand out so.
If it works, I do not know, have returned the 4-pack.
Incorrect information in the description the way lead me to a devaluation. I have no desire to buy -Wait -enttäuscht real - communicate with the seller - to return ...