Sony MDR-ZX220BT Help Manual page 29

If you cannot connect the headset, try the following.
Start the app "NFC Easy Connect" on the smartphone, and move the smartphone slowly over the N-Mark of the headset.
If the smartphone is in a case, remove the case.
Make sure that the app "NFC Easy Connect" screen is displayed on the smartphone.
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 connected via BLUETOOTH
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