DMiotech V27D-T1 0.56" 3-Digital DC 3.2-30V Voltage Meter LED Voltmeter Minimum input voltage is below the minimum measurement inaccurate or does not show. Maximum input DC 30V (above this voltage burn danger). Display 0.56" LED 3-digital tube; Display color: red. Refresh rate of about 500mS / times; Power supply. No power supply; Operating temperature: -10C~65C