Sony WI-C400 Help Manual page 24

To disconnect, touch the smartphone again.
To connect a paired smartphone, perform step 4.
Unlock the screen of the smartphone if it is locked.
Hint
If you cannot connect the headset, try the following.
Unlock the screen of the smartphone if it is locked, and move the smartphone slowly over the N-Mark.
If the smartphone is in a case, remove the case.
If you touch an NFC-compatible smartphone with the headset, the smartphone terminates BLUETOOTH connection with any
current device, and connects to the headset (One-touch connection switching).
Related Topic
How to make a wireless connection to BLUETOOTH devices
Disconnecting the smartphone by one touch (NFC)
Switching the device by one touch (NFC)
Listening to music from a device via BLUETOOTH connection
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