The single-pole design switches the line only; neutral is not switched or monitored.
The 40 A rating at 30 °C is the thermal baseline. In a 40 °C panel ambient — common in enclosed distribution boards — the continuous current must be derated per IEC 60898 derating curves; the evidence does not provide a specific 40 °C value for this variant, so the installed load should be sized conservatively below 40 A when ambient exceeds 30 °C. Maximum operating voltage is 240 V AC single-phase or 440 V AC multi-phase. For DC circuits, the maximum rated voltage is 72 V — this is not a general-purpose DC breaker for higher-voltage battery banks or PV strings. That is the mechanical endurance of the mechanism, not the electrical endurance at full rated current — expect fewer cycles under load, especially near the 40 A limit.