The Siemens 5SP3825-3 is a SENTRON main miniature circuit breaker, 3-pole, rated 25 A at AC with a 25 kA breaking capacity per EN 60898. The E tripping characteristic means it's designed for selective coordination — it holds through short-duration overloads typical of transformer inrush or motor starting, then clears fast on a hard fault.
Occupies 4.5 modular width units — that's 81 mm of rail space at the standard 18 mm per unit. Depth is 76.3 mm, height 128 mm. The enclosure depth matches the breaker body; no extra projection for the toggle. Infeed at the box terminal is standard, and supply position can be any orientation. IP40 with connected conductors — fine for enclosed distribution boards. Integrated locking slide accepts a padlock, wire seal, or cable ties for lockout/tagout. Sealable per the spec, so it meets most site isolation requirements.
At 40 °C it's 23.75 A; at 50 °C it's 22.5 A; at 55 °C it's 21.875 A. That's the number to use for the BOM, not the 25 A label.