Alpha Technologies GSM-VarioBell User Manual page 7

Mechanical parts
For easier explanation we show mechanical parts for 1, 2 and
3 modules. In one column are max 3 modules. The big set
contents max 3 columns (9 modules). For even bigger sets
you can put 9 modules set over or next each other.
Mounting box for flush mounting:
Mounting box-1 Mounting box-2 Mounting box-3
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