The Siemens SENTRON 3VA1225-5GF42-0DH0 is a 4-pole molded case circuit breaker rated 250 A continuous, with a breaking capacity of 187 kA at 240 V AC — that's the short-circuit current it can safely interrupt at that voltage level, which matters for high-fault-capacity panels near transformers or large motor banks. Breaking capacity drops across the voltage curve: 121 kA at 415 V, 75.6 kA at 440 V, 30 kA at 500 V, and 17 kA at 690 V — so the voltage class of your distribution system determines which figure governs the fault rating.
Derating starts at 55 °C (243 A), then 237 A at 60 °C, 230 A at 65 °C, and 223 A at 70 °C — so if the panel ambient runs above 50 °C, you need to account for the reduced continuous current. The 70 mm depth means it fits typical distribution panelboards without crowding the gland plate.