meter counter: 1,ratio: 100:1,200:1,400:1 2,Number:5+1 or 6+1 3,Voltage:3.5v to 6.5v ... ISO9001: 2008 meter counterKey Technical IndexJD series Electronic Type Counter for Electric Energy ... work voltage no greater than: 2.8v3,Normal working voltage: 3.5v to 6.5v4,Pulse width: 70 to 320ms5,Working ...