Sonoff SNBZ-01 Manuel D'utilisation page 7

Installation methods
1. Placed on the desktop for use.
2. Tear off the protective film of the 3M adhesive and stick the device on
the desired area.
Do not install on the metal surface, otherwise it will affect the wireless
communication distance.
The device weight is less than 1 kg.
The installation height of less than 2m is recommended.
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