Silvercrest SBL TW3 A1 Operation And Safety Notes page 59

WARNING!
Never open the housing of the product! It
has no internal parts requiring maintenance .
WARNING!
Wireless interference?
Switch the product off on airplanes, in hospitals,
service rooms, or near medical electronic
systems . The wireless signals transmitted
could impact the functionality of sensitive
electronics . Keep the product at least 20 cm
from pacemakers or implantable cardioverter
defibrillators, as the electromagnetic radiation
may impair the functionality of pacemakers . The
radio waves transmitted could cause interference
in hearing aids . Do not place the product near
flammable gasses or potentially explosives areas
(e .g . paint shops) with the wireless components
60 GB/IE