Wide range applications: EM285 circuit tester can be used to test continuity, test polarity of a voltage, check lamp, check electric motor, follow and locate short circuits, test for bad ground contacts etc. Long test lead: The cable length is about 16ft which allows you test any electrical system easily. Short-circuit protection: The unit has short-circuit protection and can test for bad ground contacts instantly. Easy operation: 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 switch forward or backward. Comprehensive 6-24V DC test kit: Do not use on AC voltage. Operation Instrcutions: Unroll the unit's cable Clamp the red to the positive terminal of the vehicle's battery Clamp the black to the negative terminal of the vehicle's battery Operation Voltage: 6-24V DC Overload Protection: 8A (When the current exceeds 8A, this item will disconnect the current automatically.) Colour: black + red Material: plastic + metal Package Contents: 1 * Circuit Tester Only the above package content, other products are not included. Note: Light 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.