The A9F05463 is a 4-pole 63 A miniature circuit-breaker from the Acti9 iC60N family, built around a thermal-magnetic trip unit with a D curve. The 36 kA Icu at 12–133 V AC (EN/IEC 60947-2) is the maximum fault current it can safely interrupt; at 220–240 V AC that drops to 20 kA, and at 380–415 V AC to 10 kA. For a 400 V distribution board, the 10 kA Icu (and 6 kA Icn per EN/IEC 60898-1) tells you the fault level the board must stay under for this breaker to clear without welding its contacts. The 4 protected poles give full isolation on all phase conductors, and the suitability-for-isolation marking (per both EN/IEC 60898-1 and 60947-2) means you can lock it off for safe maintenance downstream.
The double terminals accept 1–35 mm² rigid or 1–25 mm² flexible on top or bottom, with a tightening torque of 3.5 N·m. Strip length is 14 mm. IP20 rated, so it lives inside an enclosed panel, not on the wet side of the gland plate.