The Siemens 5SJ4140-7HG41 is a SENTRON 1-pole miniature circuit breaker with C-curve trip characteristic, rated 10 kA per EN 60898 and 15 kA per IEC 60947-2. It handles 400 V AC and 60 V DC, with a 1-module-width (18 mm) footprint that snaps onto standard DIN rail.
The 400 V AC rating suits single-phase line-to-neutral circuits in 230/400 V systems; the 60 V DC rating opens up control-circuit and battery-backed applications, though DC breaking is limited to single-pole and must respect polarity. The 1-module width (18 mm) is the standard MCB slot — it fits any 18 mm-wide DIN-rail position without adapters. The IP20 rating (with conductors connected) is standard for a DIN-rail device; the handle area is IP40, so accidental tool contact won't trip it.