The Siemens 5SL4504-8 is a SENTRON miniature circuit breaker (MCB) with a D tripping characteristic, rated 4 A at 230 V AC and breaking 10 kA per both IEC/EN 60898 and IEC 60947-2. At 40 °C ambient the continuous rating derates to 3.79 A; at 55 °C it drops to 3.45 A, so factor that into your panel thermal budget. Two-pole construction (1P+N) with switched neutral — the neutral pole opens and closes with the line pole, which is required in some regional distribution board standards and simplifies loop testing. Rated for 250 V AC single-phase and 72 V DC max, so it covers both residential lighting circuits and low-voltage DC control feeds in the same enclosure.
Snaps onto DIN rail, any mounting position. Installation depth 70 mm; overall depth 76 mm.
Current-production part.