Specifications: Two wires digital voltmeter, mini size, with reversal protection, and easy to connect. Automatically adjusts the decimal point position based on the measured voltage. LED display ensures visibility even in low-light conditions. 2-wire design allows for simple wiring and easy installation. Includes polarity protection for meter power supply. Wiring: Red Wire: Connect to Positive (2.5030V DC) Black Wire: Connect to Negative Voltage Measurement Range: DC 2.5030V (When voltage is below 3.5V, LED brightness may dim but does not affect measurement accuracy) Applications: - Measuring 18650 batteries - Measuring cell phone lithium batteries - Measuring nickel-metal hydride battery packs - Measuring car and motorcycle battery voltage Item Name: Digital Voltmeter Minimum Input Voltage: DC 2.50V Maximum Input Voltage: DC 30V Measurement Accuracy: 1% (+/ 1 digit) Display: Three-digit 0.36" LED Display Colors: Red, Blue, Green Refresh Rate: Approximately 200ms per reading Operating Temperature: -10C to 65C Features: LED display, 2-wire design, polarity protection, reverse connection protection Dimensions: 48mm x 29mm x 22mm (Approx.) Panel Cutout Size: 46mm x 27mm (Approx.) Lead Wire Length: 20cm (Approx.) Thickness: 10mm (Approx.) Mounting Hole Center Distance: 28mm (Approx.) Screw Size: M2.0 x 12 (Not included) Wire Length: Approximately 15cm (Approx.) Notes: Due to differences in lighting and screen settings, the actual product color may vary slightly from images. Please allow slight variations in dimensions due to manual measurement. Package Includes: 1 x Digital Voltmeter