The Siemens SENTRON 3VA2440-5MN32-0AF0 is a 3-pole molded case circuit breaker rated 400 A continuously across the full ambient range from 40 °C to 70 °C — no derating needed up to that ceiling, which simplifies panel thermal calculations for a motor control center or feeder section.
Dimensions are 248 mm high by 138 mm wide by 110 mm deep. Maximum power loss is 63.5 W — account for that in enclosure thermal rise calculations, particularly when grouping multiple breakers in a confined MCC bucket.