That's unusual for a thermal-magnetic breaker; the ETU350 electronic trip unit holds the rating flat through the temperature band, so you don't lose headroom on a hot switchgear lineup. Four poles give you full switching and protection on three-phase plus neutral. The interrupting ratings climb to 330 kA at 240 VAC and stay above 240 kA through 440 VAC, dropping to 187 kA at 500 V and 3 kA at 690 V — that's a high-fault package for a 40 A frame, sized for industrial mains where available fault current is substantial. If you need those, this isn't the trim.
Panel fit — dimensions and IP rating
Footprint is 140 mm wide by 181 mm tall by 86 mm deep — a standard 4-pole MCCB envelope that drops into most SENTRON 3VA switchboard and panelboard layouts without re-drilling gland plates.