It carries a 330 kA interrupting capacity at 240 V AC, which drops to 242 kA at 415 V and 3.7 kA at 690 V. That's a serious short-circuit rating for a 63 A frame; it can clear a high-fault bolted arc upstream without self-destructing, which matters when you're feeding a panel downstream of a big transformer.
That's uncommon; most MCCBs start dropping current above 40 °C. If your panel runs hot near a drive bank or a furnace wall, this one keeps delivering full rated amps.
The 86 mm depth (3.39 in) means it clears shallow gland plates and back-panel wiring troughs without sticking out.