It provides LI protection — thermal overload (L) via a bimetallic element and magnetic short-circuit (I) via a solenoid — per EN/IEC 60947-2.
The 160 A rating at 50 °C means the trip unit is calibrated for continuous current at that ambient; derate per the thermal curve above 50 °C. The instantaneous magnetic pickup is fixed at 1250 A — that's roughly 7.8 x In, which provides good selectivity with downstream breakers on a distribution panel. The 4D protected poles (all four poles protected, neutral fully rated) suit 3-phase + neutral distribution where the neutral conductor shares the same overload and short-circuit protection as the phases.
This trip unit snaps into a ComPacT NSX160 fixed-mount breaker frame.