... is a toggle function key, Press V/Hr Key once to display the Voltage then press key for 3sec. to display ... /W is a toggle function key, Press Amp Key once for output current(Amps) display, press key for 3 sec to set ... when overload.4.VA/CO2 is toggle function key, Press VA/CO2 Key once to display the VA Meter(VA= ... Vrms Arms),Then press key for 3 sec for KgCO2/Kwh Power Meter,Power ...