It protects a 1P+N circuit at 25 A rated current with 30 mA earth leakage sensitivity, curve B trip characteristic, and a 10 kA breaking capacity at 230 V AC. This is the part you spec when you need both overcurrent and earth leakage protection in one DIN-rail unit, saving a module width over separate MCB + RCCB.
The 25 A rated current at 50 °C is the continuous load it can carry without tripping — size your downstream cable and load to stay under that. The 30 mA earth leakage sensitivity is standard for personnel protection (shock hazard) per BS EN 61009-1; it will trip on any ground fault above that threshold.
Neutral on the left. IP20 rated — fine inside an enclosure, not for wet locations. The toggle gives local ON/OFF indication and the unit is padlockable with a 4 mm hasp for lockout/tagout. Position it as an outgoer feeding a final subcircuit.