This product is an electrical isolation transducer of DC micro-current measurement. Measurements for the perforated structure are with no insertion loss, high overload capacity, strong anti-electromagnetic interference capability and wide range of power supply, and the input and output are not common ground. The input signal is the DC micro-current and output is the RS-485 communication interface, it can be used to measure the DC system insulation leakage current and in DC power supply circuit insulation monitoring.