The front blue LED button, enables WPS mode.

LED status

...

Status LEDs

The front LED bar displays

...

cellular modem received signal strength.

Cellular connection technology based on the System LED color:
Red: GSM
Yellow: 3G
Blue: LTE
Green: 5G NSA
Violet: 5G SA

...

System LED have alternate modem mode indications, when cellular modem interface is enabled, System LED have have alternate indications:

blinking - connection establishment in progress, modem registered in cellular network, APN is not activated yet

red - established connection in 2G mode

yellow - established connection in 3G mode

blue - established connection in LTE mode

blinking red - SIM card not inserted

The package includes the following accessories that come with the device:

...