Com-Power Line Impedance Stabilization Networks (LISN) are intended for electromagnetic interference (EMI) testing and certification of electronic products at an EMC test laboratory. The LISN were designed and built to match the impedance characteristics given by the individual test specification. During the conducted emissions tests, the LISN isolates the equipment under test from interference from external power source. It also stabilizes the line impedance and provides a 50Ω RF output for connecting it to the spectrum analyzer. The LI-125 has a separate enclosure for each network and is shipped in pairs for single phase testing.