1、MULTIFUNCTIONAL INSPECTION: Circuit testing is ideal for checking the circuitry of a variety of vehicles, quickly checking car headlights, taillights, turn signal circuits, faulty receptacles, fuse connections, and testing other DC wires and circuits 2、SAFE AND BURN RESISTANT: The professional automatic circuit tester has a built in circuit board chip, which is safer and more durable than the traditional test lamp to prevent the car computer board from burning out 3、TWO WAY TEST: This upgraded circuit test lamp is a two way voltage tester. You can attach the crocodile clip to negative or positive ground 4、EFFECTIVE PROTECTION: The integrated structure design of probe protection cover is adopted, and the needle sleeve function is added to ensure that there will not be puncture wounds and loss of protective gear 5、PORTABLE AND PRACTICAL: Easy to carry anytime and anywhere, used for circuit testing, support DC voltage 2V, 20V, 100V