Feature: Reverse Connect Protection Range: DC4.5-30V (No need aditional power) Display: Three 0.56'' LED digital tube Display color: RED/BLUE /GREN Refresh rate: about 500mS / times Input: DC voltage ( Resolution: 1% +1 digit Power Supply: DC4.5-30V (with the input common-line) Operating temperature: -10c~ 65c Description: 1, thevoltmeterwiring is simple,only need topicktwo lines,thetablereversal protection, reversedoes not burn. 2, thevoltmeterstartvoltage is low,theredjust3.2V,just2.7VGreen,thebluejust3.0Vwill be able tomeasure correctly,startwith the price oftwo-wirevoltmetervoltageisthelowestanywhere in the world.Thiswill greatlyfacilitatetheuseofthelithium battery,18650batteryusers.Whenthevoltage is lower than3.5V,thedisplaybrightne diminishes,but does not affectthecorrect measurement. 3,inorder to achieveoptimum measurementaccuracy, thevoltmeterwillbedifferentaccording to the measuredvoltageautomatically movethe decimal pointposition.Measurethevoltagebelow 10V,displayedafterthedecimal pointtwo;10Vvoltagemeasurementsdisplayedafterthedecimal pointone.That is able totake care ofthebatteryuserneeds, but alsocater totheneedsofthehigher voltagemeasurementon the measurement accuracy. 4, thevoltmetercan be used formotorcycles, carsandothermonitoringbattery voltage,timelygraspbatterystatus.Other voltagescan also beusedformeasurementpurposes.