Wide range of applications: The circuit tester light has a DC 3-36V low voltage test range, designed to check various vehicle electrical circuits, such as car headlights, taillights, turn signal circuits, faulty sockets, fuse connections, and can also be used to test other 3-36V wiring and circuits. In addition, you can also judge the positive and negative poles of the battery through the red and green LED indicators. Clear digital display and LED indicators: The circuit light tester has an ultra-clear LCD display with a voltage reading resolution of 1V and an accuracy of 0.2V. In addition, when judging the power polarity, the two LED indicators light up in different colors to make judgments. Three-speed switch: Circuit light tester with three-speed switch. Stop at the 3rd gear, judge the positive and negative poles of the battery, and test the voltage. When judging the positive and negative poles of the battery, the red light means the positive pole of the power supply, and the green light means the negative pole of the power supply. Pure copper probe: The voltage tester adopts a pure copper probe, which does not rust and has good conductivity. It is sharp enough to easily pierce wires and penetrate narrow and hard-to-reach areas. The body is insulated so you can work safely. TPU spring wire and alligator clip: The stretched TPU spring wire can be applied to more scenes. It is more flexible than ordinary wire and easier to organize and store. The pure copper alligator clip is very strong, does not slip, and is very convenient to use.