DC 0-300V LED Display Panel Voltmeter Ammeter Digital Volt Amp Meter Tester 50A Power Supply (Measure Voltage): DC 4.5-30V.Measure Voltage Range:0-300V.Measure voltage &lt; 100V, Min Resolution: 0.1V Measure voltage &gt; 100V, Min Resolution: 1V.Measure Current: 50A forward current (need external shunt,not included).Current Resolution: 0.1A Operating Current: &lt;20mA.Display: 0.28 "LED Dual-color (red and blue).Dimensions: 48 x 29 x 21 mm.Cutting Size: 45.5 x 26.5 mm Measurement rate:  500mS / times.Accuracy: 1% ( 1 digit ).Operating Temperature: -10c ~ +65c.Operating Humidity: 10 ~ 80% (non-condensing) Package included: 1 pcs Digital Volt Amp Meter