Description: The voltmeter wiring is simple, the conventional use of two lines, red connection is positive, black connection is negative, there is reverse connection protection, connection is not burning. No external power supply is required for routine operation, and the measurement voltage can be used for direct operation, with the measurement voltage range of 2.5-32v. Wide voltage, red minimum 2.5v maximum safety pressure up to 40V, more than 40V May be damaged. When measuring the voltage below 10V, two decimal places will be displayed;When measuring voltage above 10V, one digit after the decimal point will be displayed. For other requirements or test range (4-line 0v-500v), please contact customer service. Specification: Material: Plastic Two-wire Measurement range: DC 2.5-30V, 2.7-30V, 3-30V Min. input voltage: DC 2.5V, 2.7V, 3V Max. input voltage:DC 30V(Higher than this voltage is has a risk of overburning) Permissible error: 1%(1 digit) Display mode: three digit 0.28'LED digital tube Speed ratio: about 200ms/time Current Consumption: <20mA(Generally 5-15 mA) Working temperature: -10~ +65 WIre Length:140mm/5.51inch All Size: 0.36inch Size: 33x15x10mm/1.38x0.04x0.39inch 0.28inch Size: 30x10x8mm/1.18x0.39x0.31inch Package Includes: 1 Piece 2-Wire Digital Display DC Voltmeter High Precision Anti-protection