Features: Auto Repair Industry: Especially suitable for automobile, electric vehicle maintenance technicians and families, enterprises, vehicle maintenance, etc. Generator Charging System: When properly connected, start the generator, the output voltage will be displayed on the LED display, and the right LED indicator will light up to indicate the generator status. With LED Reverse Display Screen: The test shows a reverse display, and the measured values can be seen clearly at night or in the dark. Car Battery Detection: When connected, the LED display will display the voltage under test, and the LED light will light up to indicate the battery status. Alligator Clip: Correctly connect the positive electrode "+" and the negative electrode "-" connect the reverse electrode, the display screen will not display. Specifications: Model: BT-171 Material: ABS Test Method: Positive and Negative Test Clip Test Voltage: 12V LED Light: Red Yellow Green Blue White, colorful lights LED Lights Related Instructions: FULL: Battery is in normal condition MEDIUM: The battery voltage is slightly lower and needs to be charged LOW: The battery is low and needs to be charged, buzzer alarm EMPTY: The battery is completely dead and needs to be charged HIGH: High output voltage of alternator GOOD: Alternator output normal DEAD: The battery voltage is too low, and the buzzer alarm prompts that there should be a problem with the battery. At this time, the battery should be checked by a professional engineer to see if it is replaced. RECERSE: The battery tester is connected to the battery terminal in reverse, and the buzzer alarm prompts. Item Size: 115 * 70 * 20mm 4.53 * 2.75 * 0.79in Item Weight: 78g 2.75oz Package Weight: 100g 3.53oz Package Size: 14 * 8 * 4cm 5.51 * 3.15 * 1.57in Package List: 1 * Battery Tester 1 * User Manual (English)