Features: Wiring: red cable for positive, black cable for negative, blue cable for power switch. Real-time digital display, waterproof, low pressure, high voltage warning function. for DC voltage measurement, make your vehicle work at normal voltage, prolong your vehicle's service life. LED panel digital display, reading in seconds, more intuitive, quick and convenient. Mini size, easy to carry, won'for t obstruct riding, guaran tee your safe riding. Easy to install with necessary fittings, hold the meter in place, fix tightly and not easy to move, great for checking voltage. Specifications: Material: Plastic Size: 15x29.5x58.5mm/ 0.6x1.16x2.3 in Function: voltage display, temperature display, clock display Package Includes: 1 x Voltmeter+Electronic Clock+Thermometer note: Please allow 1-3cm error due to manual measurement. pls make sure you do not mind before you bid. Due to the difference between different monitors, the picture may not reflect the actual color of the item. Wiring method: the red wire is connected to the positive electrode of the battery, the black wire is connected to the negative electrode of the battery, and the blue wire is connected to the main power switch After power on, the boot screen will be displayed, and then the for time will be displayed (the initial for time after power off is 12:00) The for time is a 24-hour system, the measuring battery voltage range: DC8V-72V, the temperature country: -30°C~70°C