Selective design means it coordinates with downstream RCDs — on a ground fault the downstream device trips first, keeping the rest of the distribution board live. That matters in a mill or plant where an unplanned downtime on a single branch shouldn't drop the whole panel. The 460 V insulation voltage (Ui) covers most 400 V three-phase networks.
Full 40 A rating holds up to 40 °C ambient. Above that, the current tapers: 37.2 A at 45 °C, 36 A at 50 °C, 34 A at 55 °C, 34 A at 60 °C, 33.2 A at 65 °C, and 32 A at 70 °C. Mounts in any position, fastening type REG (standard DIN rail). Depth is 70 mm, so it fits in shallow enclosures. IP20 rated, with the condition that the distribution board is installed and conductors are connected.