AC single phase 4 bits Digital Voltage meter

6 in 1 AC electric paramter gauge, measure active power watt, estimated annual electricity consumption KWH (power eclectricity consume by 365days**hours per one year), power factor, Voltage, Current, frequency, actual electricity consumption KWH and time counting . Pressing switch button in the back can choose different parameter display. Memory store after power off : Meter can store the last switch button setting even after power down. Fox example, you set the switch button