Siemens SENTRON 5SY7425-6 — 4-pole B-curve MCB, 25 A
It sits in a standard 4-modular-width (4 MW) DIN-rail footprint — 72 mm wide, 90 mm tall, 76 mm deep — and mounts in any position, which helps when you're squeezing it into a crowded panel. Breaking capacity is 15 kA per EN 60898 and 25 kA per IEC 60947-2, with a DC rating of 15 kA per IEC 60947-2. That covers most industrial distribution boards and motor control centers; the higher IEC figure matters when the fault current at the panel is above 15 kA.
Thermal derating and ambient limits
The 25 A rating is at 35 °C. At 40 °C it derates to 24 A, at 50 °C to 22.98 A, and at 60 °C to 21.9 A. If your panel runs hot — near a drive or in a sealed enclosure — check the actual load against the derated figure. The breaker also handles humidity up to 95% at 55 °C, tapering to 35% at 75 °C.