Question about Arctic Z1 Basic

It is definitely too deep for that.

Arctic specifies a height of 41 cm for the tube.

https://www.arctic.ac/ch_de...

There are also holders that can be mounted on the wall. These are then of course "unlimited" in height. However, not everyone can / is allowed to drill holes in the wall.

I went to the locksmith and had it extended for 50 euros. To mount two 27 inch monitors on top of each other, you need a minimum height of 75 cm. Stability is top, I didn't have to do anything extra.