ITEM NAME:New Two Wires Digital Voltmeter Blue LED Display DC3.0-30V Voltage Meter A#S Product Description Description: Feature: Two wires digital voltmeter, mini size, with reversal protection, and connect easily. According to the different measuring voltage, automatically moving the position of the decimal point. Measure Voltage Range: DC2.50-30V. When the voltage lower than 3.5V, the brightness of the LED display is dimmed, but does not affect the correct measurement. Min Input Voltage: DC2.50V Max Input Voltage: DC30V Measurement Accuracy: 1% (+ / - 1 digit) Display: Three digit 0.36" LED Display Color: Red, Blue, Green Refresh Rate: about 500mS / times Power Supply: No need other power supply Operating Temperature: -10Â °C - 65Â °C Size: 3.7 x 2.3 x 1.5(cm) Thickness: 10mm Mounting Hole Center Distance: 28mm Screw Size: M2.0 x 12(This item NOT included) Wire Length: about 15cm Weight: 5G Wiring: Red wire: Measure Voltage +,(2.50-30V DC) Black wire: Measure Voltage - Some applications: Measure 18650 batteries Measure Cell-phone Lithium Batteries Measure Nickel-hydride Battery Pack Measure Cars Motorcycles Battery Voltage Etc. Included: 1 x Two Wires DC3.0-30V Digital Voltmeter.Display: Three digit 0.36" LED. Display Color: Red, Blue, Green. Size: 3.7 x 2.3 x 1.5(cm). Wire Length: about 15cm. Weight: 5G. If item is defective after 3 months, you can still send it back to us.