The Siemens 3VA1216-6EE42-0AA0 is a 4-pole IEC molded-case circuit breaker in the 3VA1 platform, rated for a 250 A frame with a class H breaking capacity of 70 kA at 415 V AC. The TM220 thermal-magnetic trip unit gives you an adjustable overload protection band from 112 A to 160 A (Ir) and a fixed magnetic short-circuit pickup at 10 x In (1600 A). The thermal element handles sustained overloads on feeders or large loads; the magnetic element clears hard shorts fast.
The nut keeper kit (included) holds the busbar or cable lug nuts captive during wiring — saves a hand when torquing down in tight gland-plate layouts. Four-pole means it occupies a 4-module width on the rail; plan your fill factor accordingly.