Long probe and alligator clip: The long probe with an alligator clip allows you to reach the right place. The tester's sharp steel probe can easily pierce the wire insulation. Wide Application: It can be used for passenger cars, RVs and even trucks. A professional tool for detecting open circuits, fuses, adjusting signal lights, headlights, taillights, etc. LED work indicator: When the circuit connection is completed, the LED on the handle lights up to indicate that the power is on. And the brightness of the light will be different with different voltages measured. Bidirectional Voltage Tester: This upgrade circuit test light is a bidirectional voltage tester. During the positive connection, the red LED will be on, and during the negative connection, the green LED will be on. Don't worry about losing: the integrated structure of the probe protection cover makes this automotive fuse tester hard to lose. And it is lightweight and compact, convenient to carry and take wherever you go.