The Schneider Electric G12T4A63 is a GoPact MCCB 125 — a 4-pole moulded-case circuit breaker with a 63 A rating at 40 °C and a 10 kA breaking capacity at 380/415 V AC. It uses a thermal-magnetic TM-D trip unit for LI protection (overload and short-circuit).
If your panel runs hotter, you will need to derate. The TM-D trip unit gives you fixed thermal (overload) and fixed magnetic (short-circuit) protection curves. The thermal element is calibrated for the 63 A rating; the magnetic pickup is set at the factory. This is a no-nonsense, non-adjustable trip unit — what you see is what you get, which keeps ordering simple but means you cannot fine-tune coordination on site. Mechanical durability is 30,000 cycles, which covers switching without load for maintenance or isolation.