Ubiquiti Networks PowerBridgM - Manual (Page 4)

LEDs
Power The Power LED will light green when the
device is connected to a power source.
Ethernet The Ethernet LED will light steady green
when an active Ethernet connection is made and
flash when there is activity.
Signal In airOS, you can modify the wireless signal
strength threshold values for each LED on the
Advanced tab under Signal LED Thresholds. The
default values are shown below:
LED will light red when the wireless signal
strength is above -94 dBm.
LED will light amber when the wireless signal
strength is above -80 dBm.
LED will light green when the wireless signal
strength is above -73 dBm.
LED will light green when the wireless signal
strength is above -65 dBm.