The Schneider Electric A9KF71363 is a 3-pole Acti9 K60 miniature circuit breaker rated at 63 A with a C curve (magnetic trip 5–10 x In). It breaks 10 kA Icn at 415 V AC 50/60 Hz per EN/IEC 60898-1 — that's the standard for household and similar installations, so it's sized for distribution boards in commercial or light industrial panels where the prospective short-circuit current stays under 10 kA.
The 54 mm width occupies 6 x 9 mm pitches — three poles at 18 mm per pole, so it fits a standard 3P MCB slot. Strip 14 mm. IP20 finger-safe — fine inside an enclosed panel, not for wet locations.