Rated continuous current is 40 A across the 40 °C to 50 °C ambient range, derating slightly to 39 A at 55 °C and 37 A at 70 °C. The thermal pickup Ir adjusts from 28 A to 40 A; the magnetic short-circuit pickup Ii is fixed at 10 × In. That 10× multiplier means instantaneous trip at 400 A — tight enough to ride through motor inrush on a 40 A feeder but still clear a hard fault fast. Breaking capacity is the headline here: 121 kA at 240 V AC, 76 kA at 415 V AC, and still 53 kA at 440 V. At 500 V the rating drops to 11.9 kA, so verify your system voltage before committing.
Integration note
Front connection means the line and load lugs are accessible from the front — no rear-bus bar required.