Model: PZEM-004T 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) Different batches may result in different product appearances, text, and colors, which do not affect usage Shell Colour:Clear Blue Material:PCB Package Contents: 1 x Meter 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.