Mono Earbud Mode
Mono mode for Left or Right earbud:
Take the left or right earbud out of the charging case, it will power on and enter pairing mode automatically. Enable Bluetooth on your device and tap "HE180250" on the list to connect. If the left or right earbud has been used as Mono mode last time, it will connect with your last connected device automatically once it was pick up from charging case.
To Exit Mono mode:
Take both earbuds out of the charging case and they will pair together again.
Alternatively if one is connected and one isn't, simply hold multi function button for 5 seconds on the earbud that is not connected.