Coulometer, ampere & voltage meter 1) measure voltage/current/power factor/Kwh,etc 2) 4-20mA analog output 3) 2 alarm, RS485 Coulometer, ampere ... digit LED display, easy to read;2) To measure voltage, current, power factor, active power, reactive power, apparent power, HZ, KWH ... setting in software menu;6) Some model with 4-20mA analog current output;7) Some model with RS485 communication function.