switel WT257 Mode D'emploi page 57

You will find the connecting socket on the upper side underneath a
cover. Open the cover on the upper side of the radio and insert the
plug into the socket. The loudspeaker and microphone in the radio are
switched off when the headset is in use.
Make sure that the microphone opening remains unobstructed.
When using the headset, we recommend that the keypad lock
on the radio is activated so that no settings can be changed
unintentionally.
- Operation -
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