DROK 100282 0.56" Digital DC Voltmeter Panel Volt Meter Gauge LED Display 0-300V Voltage Tester Operating voltage: 3.3 ~ 30V (with reverse protection) Test voltage: 0 ~ 300V (100V resolutions: 0.1V;  100V resolution: 1V) Operating Current: &lt;20mA; Measuring rate:  500mS / times Display: 0.56 " LED, red / blue / green; Accuracy: 1% ( 1 digit) Dimensions: 48 x 29 x 21 mm; Installation hole: 45.5 x 26.5 mm