The Siemens 5SL6250-6 is a 2-pole miniature circuit breaker from the SENTRON 5SL series, with a B-curve tripping characteristic rated at 50 A at 400 V AC.
At 36 mm wide (2 modular units), it takes two 18 mm slots in a distribution board. IP20 with conductors connected, so it lives inside a closed panel or enclosure, not exposed to washdown.
Thermal derating and environment
Rated 50 A at 30 °C ambient. At 40 °C it carries 46.97 A; at 55 °C it carries 42.01 A.
If you are filling a BOM line or stocking a spare, this is a standard SKU, not a phase-out risk.