SMAKN&reg; Digital Voltmeter Guage AC 80-500V 110V/220V Blue LCD Alternating Voltage Volt Panel Meter Measurement Range: AC 80-500V,No need power supply: Two wires measure directly Display: LCD, high-definition blue backlight, 3 1/2, character height 20mm Accuracy: 0.5% +/- 2 digits;Sampling Rate: 2.5 times / sec Dimensions: 79 x 43 x 31mm Usage:substation automation, distribution automation, testing equipment, voltage regulator and etc.