urmet domus IPerCom 3.1.0 System Technical Manual For The Installer page 678

Joining flush-mounting boxes
Flush mounting boxes can be assembled with suitable spacers, also used as wire hole. Up to 3 4-module
flush-mounting boxes can be assembled (12 modules in total). If wall cover frames are used, instead, up to
3 3-module boxes (9 modules in total) can be assembly, joining them on the longer side. All spacers are
empty, to allow the passage of wires from a box to another one.
678 MT124-032N