Its basically three led's in one,
And monitors the voltage of your car battery,
Its remains green until voltage drops below 12.0V
then it turns yellow until voltage drops below 11.5V
Then it turns red for anything lower.
I had considered purchasing one and fitting to the ST gauge pod bottom centre between the two gauges,
Since ill be fitting two amps to th3 car in spring, there will be a heavy drain on the battery; if listening to the stereo with the engine off,
So having this warning indicator visible on the dash would in theory give early warning of battery drain, leaving enough time to start the engine saving the occupants from becoming immobilised due to a drained battery.