It is commonly used in qualitative experiments for various microamp current and it must be connected in series.

  DIS LAB for Primary school--Micro Current Sensor   Description

Model: ZJKY 1002

Description:  Different from Current Sensor, Micro Current Sensor has two shielding wires.

Positive numbers will be displayed if current flows from the red wire to the black wire, and vice versa.

DIS LAB for Primary school--Micro Current Sensor