Button operations do not work.

Check the following:

• The connected device and both the (L) left unit and (R) right unit of the headset are turned on.
• Make sure that the BLUETOOTH connection is not disconnected. If it is disconnected, set the BLUETOOTH connection again.
• Reset the headset. Set the headset on the charging case. When the charging starts, the connection will be reset.

• If the button operations still do not work correctly, initialize the headset.
• To initialize the headset, remove the headset from the charging case, press and hold the button on (L) left unit for more than 2 seconds to turn off the headset ((L) left unit and (R) right unit), and then press and hold both the button on the (L) left unit and the button on the (R) right unit for more than 15 seconds at the same time.
  The indicator (red) goes into the flashing state then the indicator (blue) flashes 4 times, and the headset is initialized.
  The headset is reset to the factory settings and all pairing information is deleted. In this case, delete the pairing information for the headset on the device which has been connected, then pair the headset with the device again.