The unit is the best electrical tester for reducing diagnostic time in automotive electrical systems .Its long cable makes your testing easily. After a simple hook-up of the unit to the vehicle's battery, automotive technician can conduct a positive or negative battery current to the tip by rocking the power switch forward or backward.The unit has short-circuit protection and can test for bad ground contacts instantly. It allows you to track and locate short circuits.It can also test for continuity with the assistance of its auxiliary ground lead. It is a comprehensive 6-24V DC test kit.Package List1x Circuit tester1x User manual (in English)THE GUIDE DIAGRAMApplications:1. Test for continuity2. Test for polarity of a voltage3. Check switches, relays and the on-off of diodes, fuses and circuits4. Test for polarity of electric cables and plugs5. Track and locate short circuits6. Test for bad ground contacts Specification:Operation voltage: 6-24V DCCable length: about 4mOverload protection: 8A (When the current exceeds 8A, this item will disconnect the current automatically.)Weight: about 200gDo's and don'ts:1. Do not use the item around explosive gas, vapor, or dust. When the power switch is pressed (or rocked), battery current is conducted directly to the tip which may cause sparks when contacting ground or certain circuits.2. The unit is not to be used with 110/220V house current, it is only use for DC 6~24V systems.3. Do not use on AC voltage.4. After you finishing checking vehicle, correctly restored all the connection-s which you disconnected.5. Always follow the instructions and procedures indicated in the vehicle's service manual before attempting to disconnect any part or subsystem of the electrical circuit.6. Never touch any dangerous part of the vehicle with your hand for safety. Don't touch any live conductor with hand or skin.7. Don't use it if it is damaged.8. Some components of vehicle work on low voltage, they cannot withstand the voltage allied by the item. To avoid damage for these components, don't use the item to apply voltage directly or indirectly.9. Before driving, please always make sure that the vehicle is safe and reliable.10. Don't use this item when driving.