Hi,

I've just got an ADI-4DD and i was a little surprised to find no holes on the sides of the unit for the RME rack adaptor , like there are on the UC , UCX and ADI-2.
I know there is a rack shelf that can hold two units side by side , but I wanted to use the other type that neatly holds one unit in the middle.

Is there a technical reason for this?

Its a great little unit !