Features: Front lighting : Only need to put the redness and black clips on the positive and negative clips on the car battery the electrode can be used , which is convenient for detection and maintenance in the dark place , and can also be used as a lighting lamp. Voltage display : the redness and black clips can be printed on the positive electrode and negative electrode . the voltage value of the storage battery is displayed in blue; Voltage polarity test : Without pressing the key on the tester , it can be used before the tester the surfaces probe probes the unknowns polarity contact ( contact ) on the car to check whether it is charged or positive Polarity ( LED bright redness ) or negative polarity ( LED green); Polarity output : Press the ammonium bond on the tester ( front pressure "" or back pressure "" ) , Make the probe on the tester with a positive voltage ( LED bright redness ) or a negative voltage ( LED Green ) . At this time , the dimensional device can be check according to the electrical polarity of the device to be repaired and test component grounding. Overloads power off protections : If the current is too large or the load is too large in the power distribution process , the LED will be instantaneous Change from redness to green with a buzzer warning that should be disconnected or test for protections storage battery; Specifications: Material:ABS Voltage:DC3.5V-36V Overloads Protections Current:8A Rating Current:1-8Amp Working Temperature: -10-60 Cable Length:Approx.4.5meters/14.76Ft Note: Please allow 1mm errors due to manual measurement. Due to the difference between different monitors, the picture may not reflect the actual color of the item. Package includes: 1x Automotive Circuit Tester