This is a tool used for testing LED backlights in TVs and other LED light sources ,it features automatic detection of output voltage and current ,allowing it to test LED backlights and beads of various sizes ,it offers a high brightness ,the tester operates with an input voltage of AC 85V-265V and an output voltage of DC 0-300V. It is designed for direct measurement and automatically adjusts the voltage and current ,identifying lamp beads and light shafts.