Breaking capacity is the headline here: 187 kA at 240 V AC, 121 kA at 415 V and 440 V, 75.6 kA at 500 V, and 17 kA at 690 V. At 690 V the 17 kA figure still covers most industrial motor-drive feeds; just verify your available fault current against the curve before committing the BOM line.
Thermal derating — don't spec the 400 A number alone
At 55 °C it drops to 385 A, then 370 A at 60 °C, 355 A at 65 °C, and 340 A at 70 °C. The 96 W max power loss at full load also factors into enclosure thermal rise; a small stainless box with no fan will cook the trip unit if you ignore it.
What you won't find inside
This variant has no undervoltage release, no voltage trip, no communication module, no phase-failure detection, and no ground-fault monitoring. It's a straight line-protection breaker — overload and short-circuit only. If your spec requires shunt trip, UVR, or ground-fault integration, you need a different 3VA2 order code with those options factory-installed.