Overview: This document describes the specification of the PZEM-004T AC communication module, the module is mainly used for measuring AC voltage, current, active power, frequency, power factor and active energy, the module is without display function, the data is read through the TTL interface. PZEM-004T-100A: Measuring Range 100A (external transformer) Model: PZEM-004T((Row of stitches version)) Different batches may result in different product appearances, printed text, and colors, which do not affect usage Material: PCB colour: green Package Contents: 4 x Module Only the above package content, other products are not included. Note: Light reflection and different displays may cause the color of the item in the picture a little different from the real thing. The measurement allowed error is +/- 1-3cm.