1.[UNIQUE DESIGN- ANTI-LOST NEEDLE GUARD PROTECTION]: Adopt the integrated structure design of the probe protection cover, needle guard function is added to ensure that there will be no stab wounds and the guard will not be lost. Convenient to carry and take it wherever you go. 2.[LED INDICATION, BIDIRECTIONAL VOLTAGE TESTING]: This upgrade circuit test light is a bidirectional voltage tester. You can attach the alligator clamp either to negative or positive ground, there is also a light emitting diode on the circuit board for polarity indication, red light indicates positive polarity and green light indicates negative polarity. 3.[BUZZER WARNING & OVER-VOlTAGE WARNING]: The LED light will be on and there will be a buzzing sound during the test. If the voltage exceeds 60V during the test, the screen will display: 'ol', RED and GREEN led flashing together, please stop the test immediately! 4.[COMPUTER SAFE, STURDY & FLEXIBLE]: The professional auto circuit tester has a built-in circuit board chip, which is r and more sturdy than traditional test lights and prevents the car computer board from burning out. Spring wire can be ly stretched up to 102 inches, with a wide measuring area; Anti-bending design of the tail wire, no need to worry about bad of the line. 5.[WIDER VOLTAGE RANGE] Compared with the auto electrical tester on the market, the maximum voltage measured is only 48V, but the maximum voltage that this technology can measure is upgraded to 60V. This circuit test is ideal for checking various vehicles electrical circuits, quickly check automotive headlights, taillights, turn signal circuits, faulty sockets, fuse connections, also for testing other 4-60V DC wirings and circuits.