Fangrui Product Details 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 Vehicles 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 Will 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