(blue).
Selecting the sound quality mode
Turn on the headset by pressing the 
POWER button for more than 2 seconds while holding the VOL + or VOL – button down.
To select the “Priority on sound quality” mode
When the headset is in the “Standard” mode, turn it on while holding the VOL + button down. The “Priority on sound quality” mode is selected.
From the “Priority on stable connection” mode, turn on the headset while holding the VOL + button down. Turn off the headset once, then turn it on while holding the VOL + button down again.
To select the “Priority on stable connection” mode
When the headset is in the “Standard” mode, turn it on while holding the VOL – button down. The “Priority on stable connection” mode is selected.
From the “Priority on sound quality” mode, turn on the headset while holding the VOL – button down. Turn off the headset once, then turn it on while holding the VOL – button down again.
Notes
The playback time may become shorter, depending on the sound quality and the conditions under which you are using the headset.
80