Features:1.the voltmeter with full enclosure， potting fully waterproof design， a long soak in the water can still work without damage， more moisture， oil， dust， vibration.2.the voltmeter display uses LED digital tube 0.28 inches.3.the voltage meter wiring simple， just take two lines in the table have reverse protection， reverse does not burn.Specification:Dimensions: As shown in the picturesType: 3 digits 0.28″Led color: blue/red/green/yellow(Please leave note which color you want，or i will send you red color.thanks).Range: dc 3.50-30.0VSupply voltage: DC3.50-30.0VCable length: 85mmFixed hole diameter: 3mm(approx.)Reading per second: 2The power consumption: Static about 15 mAAccuracy: 1% (±1 digit)Operating Temperature: -10°C~65°CPotting material Epoxy-resin GlueWiring:Red: Power Supply +， Measure +Black: Power Supply -， Measure -Reverse polarity protection: YesApplication:used for battery voltage measuring on electric vehicles， electric cars， electric motor cars， and so on. Package Included:1x DC Voltmeter(color as you choice)