Wide range of applications: The circuit tester can be used to test continuity, test voltage polarity, check lights, check motors, track and locate short circuits, test poor ground contact, etc. Simple operation: After simply connecting the device to the vehicle's battery, the automotive technician can conduct the positive and negative current of the battery to the tip by shaking the power switch forward or backward. Do not use under AC voltage. Working voltage: 6-36V DC Overload protection: 8A (When the current exceeds 8A, this item automatically disconnect the current.) Product function: A practical auxiliary tool designed during the repair and inspection process of automotive electrical circuits. It can be used to test battery voltage value, voltage polarity, conductivity, check lights, check motors, track and locate short circuits, test ground contact and light failure. Extra-long test line, cable length of about 4.5 meters, allows you to easily test the electrical system of any part of the car. External power supply: 12V or 24V DC power supply is provided through the vehicle battery. Overload protection current 8A Rated current: 1-8Amp Product name: Automotive electrical circuit tester Cable length: 4.5 meters Operating Instructions: Unfold the unit's cable Clamp the blue clip to the positive terminal of the vehicle's battery Clamp the black clip to the negative terminal of the vehicle's battery Colour: Blue+Black Material: ABS Package Contents: 1pcs Car Electrical System Tester Only the above package content, other products are not included. Note: Light reflection and different displays may cause the color of the item in the picture a little different from the real thing. The measurement allowed error is +/- 1-3cm.