DD7041 series digital Voltmeter is an intelligent meter used to measure AC Voltage. It is cost-effective, miniature, flexible, and is useful for voltage stabilizer, machines and other devices for measuring voltage Voltages: 50-500V AC Resolution to 1V; Accuracies to +/-1%,+/-2LSB Reliable, long life, Mcu measuring Sample Speed: about 10 times/sec. LED Size/ Color: 3 digit, 0.56',Red Maximum Display: 500 Over Range: Display 'H' Dimension: 70*41mm Mounting Size : 68*38mm. It is self Powered device, so no additional Auxiliary supply is needed.