The Siemens SENTRON 3VA2340-5JP32-0DA0 is a 3-pole molded case circuit breaker rated for 400 A continuous at 40 °C — that's your feeder or main disconnect for a 400 A bus, not a branch device.
Built-in undervoltage release and comms — one less add-on module
It also carries a communication function onboard, which on the 3VA platform typically means it can talk to a higher-level controller or energy-management system. The auxiliary switch design is listed as "without", so if you need a remote status contact, plan on adding an auxiliary switch block.
Footprint and panel fit
Dimensions are 110 mm deep, 138 mm wide, 248 mm tall. The width is the key constraint for multi-breaker panels: at 138 mm, three across eat 414 mm of backpanel width before you account for phase barriers.