The Siemens SENTRON 3VA2163-7MS36-0DL0 is a 3-pole molded case circuit breaker rated for 63 A continuous across the full 40 °C to 70 °C ambient range — no derating needed as the panel warms up. Interrupting capacity hits 330 kA at 240 V, dropping to 242 kA at 415 V and 440 V, then 187 kA at 500 V; at 690 V it's still 3.7 kA. That's a lot of fault-clearing headroom for a 63 A frame, meaning it can sit upstream of a high-fault panel without cascading.
This MCCB is designed for starter protection — the built-in undervoltage release (UVR) and the auxiliary switch block (2 aux + 1 trip alarm + 1 electrical alarm) mean it's wired for motor control center duty right out of the box. Panel cutout is 105 mm wide by 181 mm tall by 86 mm deep; that 86 mm depth is the dimension that matters when you're sliding it into a tight backpanel against a deadfront.