Rated 125 A at 230...415 V AC, it provides 1000 mA AC-type residual current protection with a selective (time-delayed) trip characteristic, meaning it coordinates downstream so only the faulted branch clears first.
The 125 A rated current (In) matches high-current outgoing feeders or incomer positions in distribution boards. The 1000 mA sensitivity is a selective (delayed) trip — it's not for personnel protection (which requires 30 mA) but for equipment-level earth-fault protection with coordination downstream. AC-type detection handles sinusoidal residual currents only; if your loads include rectifiers, VFDs, or switched-mode supplies, you'd need Type A or Type B instead. The 230...415 V AC operational voltage covers single-phase and three-phase networks up to 415 V phase-to-phase.
Electrical connection to the MCB is by screws (tunnel terminals accepting 1...35 mm² flexible or 1...50 mm² rigid). The 2-pole (2P) format fits single-phase or two-wire circuits.