At 240 V it interrupts 76 kA; at 415 V that drops to 53 kA, at 440 V to 32 kA, and at 500 V to 8 kA.
Derating and thermal limits
At 55 °C it derates to 39 A, at 60 °C still 39 A, at 65 °C to 38 A, and at 70 °C to 37 A. In a tightly packed panel — say a 40 °C internal ambient with a row of breakers side by side — you can load it to 40 A continuous without worrying about nuisance tripping. Max power loss is 14 W, which is modest for a 40 A frame; that helps keep the enclosure from cooking.
The 3VM1040-3ED32-0AA0 measures 70 mm deep by 76.2 mm wide by 130 mm tall. The 76.2 mm width (3 inches) is a standard 3-pole MCCB footprint — it'll drop into a panel that was laid out for a 3-pole frame without re-drilling the backplate.