AC 70-500V LED Digital Voltmeter Voltage Meter Volt Instrument Tool 2 Wires Red Green Blue Display 110V 220V DIY 0.56 Inch Description: This voltmeter's wiring is simple, it only need to connect two wires, the red wire is to connected to positive pole, the black wire is to connected to negative pole, There is protection when the wires aren't correctly connected, the electric circuit won't be bumed.It has reverse connect protection. This voltmeter doesn't need external drive working power, it can work with measuring voltage, the working voltage's range is70-500v Good stability and high measurement accuracy. With trimmer potentiometer. Easy to read, install and use. No need external power supply. Specifications: Measuring range: AC70V-500V Power supply range No additional power supply needed, direct use of the measured voltage as a power supply, range: AC70V-500V Maximum input Package Included: 1pcs Voltage meter head Notes: AC500V. Input voltage higher than 500V may be permanently damaged! Allowable error: 1%; Input impedance> 1M ohms Working current red