This device is designed to check and test 12V batteries and the dynamo (alternator) in vehicles.
It can assess the battery's charging level, the functional performance of the dynamo, and the battery's starting capability.
The tester features LED indicators to display the results, showing voltage levels for both alternator and battery tests (e.g., 14.5V Fault, 13.5V Good for alternator; 12.5V Full, 5.0V Low for battery).
It's described as a portable 12V LED digital battery tester.