Sony SRS-X99 Help Manual page 193

Reaction area
Rear side
1. UPDATE button
Indicates the status of the unit's software update.
2. LINK indicator
Indicates the status of the speaker's network connection.
3. VOL (volume) -/+ buttons
Tap to adjust the volume.
The (on/standby) indicator and reaction indicator flash according to the volume adjustment when tapped.
4. (on/standby) button/indicator
Tap to turn the speaker's power on and off.
The power status of the speaker is indicated by the lighting or flashing of the indicator.
5. Remote sensor/Reaction indicator
When the speaker receives signals from the supplied remote control, the reaction indicator (remote sensor) flashes.
Also, the indicator flashes according to the volume adjustment of the speaker.
6. N-Mark
184