Small and portable,High sensitivity, fast response, simple and convenient operation. Widely used in the auto repair industry: especially suitable for automobile and electric vehicle maintenance technicians and family and corporate vehicle maintenance and repair, etc. With reverse connection alarm and overvoltage protection function, the red clip is connected to the positive pole "+" and the black clip is connected to the negative pole "-". If the connection is reversed, the LED display not display, the REVERSE indicator light up and an alarm be issued. The LED reverse display screen is clear even in backlight. The reverse display screen is displayed when testing. The measured value can be clearly seen at night or in the dark to assist the measurement work and read easily.After correct connection, the LED display screen show the real-time voltage of the measured voltage and the LED light light up to indicate the battery status. Test the status of the generator charging system: During the test, please keep the tester correctly connected to the battery terminal, and then the generator. At this time, the output voltage be displayed on the LED display, and the right LED indicator light up to indicate the generator status.No need to install the battery, easily complete multiple tests, use real-time measurement. Test voltage: 12V Test method: positive and negative pole test clip Product material: ABS insulation material LED light: red/yellow/green/blue/white colored lights Tips: The product may be updated constantly,Due To Different Batches, The Actual Product May Have Slight Differences Or Color Differences, Which Does Not Affect Use Colour:Black Material:Plastic Package Contents: 1x Battery 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.