Breaking capacity hits 121 kA at 240 V AC and 75.6 kA at 415 V AC — enough to clear high-fault utility feeds or large motor branch circuits without cascading upstream.
The 400 A rating holds flat from 40 °C up to 50 °C, then derates to 392 A at 55 °C and 367 A at 70 °C. That thermal curve means you can run it near full nameplate in most enclosed panels without derating for ambient rise — but if the panel hits 55 °C, you lose 8 A. The 121 kA at 240 V is the maximum interrupting rating; at 690 V it drops to 11.9 kA, so verify the available fault current at your service voltage.
The 4-pole body takes up about 7.24 inches of rail width; plan your enclosure depth to clear the 110 mm plus wiring space behind the line and load lugs. Power loss is 92.1 W maximum at rated load, so factor that into your thermal budget for the enclosure.