UPGRADED UNIQUE DESIGNSharp stainless steel probe can pierce insulation and reach tight areas. 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. DIGITAL LED & BUZZER BIDIRECTIONAL INDICATIONThe alligator clip and probe of voltage tester can be connected to the positive and negative poles bidirectionally. Buzzer pulse once with red light on when is positive, beep twice shows negative pole with green light. LED not backlight digital readouts on the voltage electrical tester makes the data clear & visible under any light conditions. COMPUTER SAFE, STURDY & FLEXIBLEThe professional auto circuit tester has a built-in circuit board chip, which is safer and more sturdy than traditional test lights and prevents the car computer board from burning out. Spring wire can be freely stretched up to 140 inches, which offered a w