This MCCB's interrupting rating changes with system voltage, which is common for molded case breakers. At 240 V it can clear 52.5 kA of fault current; at 415 V that drops to 32 kA; at 440 V it's 13.6 kA; and at 690 V it's 7.5 kA. If you're on a 480 V system, use the 440 V column as a conservative bound.
Above that, it steps down: 19.2 A at 55 °C, 18.8 A at 60 °C, 18.4 A at 65 °C, and 18 A at 70 °C. For a lube-route tech or MRO planner: if this breaker sits near a hot motor starter or a sun-baked enclosure, check the actual panel temperature against that derating curve — a 20 A breaker pulling 18 A continuous at 70 °C is still fine, but don't load it to nameplate at those temps.