PZEM-004T V3.0 or Version 3.0 is the upgraded version to replace the old PZEM004T V1.0. The old version has been sold out in most of the online store and no produce anymore. The updated version of PZEM004T is best for the DIY project, where we need to measure the voltage, current, power, energy, frequency, Power factor (frequency and PF is extra added in the new version) using Arduino/ESP8266/Raspberry Pi like open-source platform.