The Siemens 5SL4604-6 is a SENTRON miniature circuit breaker rated 400 V AC with a 10 kA breaking capacity per EN 60898 and IEC 60947-2. It's a 4-pole (3P+N) unit with a B-curve tripping characteristic, rated 4 A at 30 °C.
The 10 kA breaking capacity at 400 V AC means this MCB can safely interrupt a fault current up to 10,000 A without welding its contacts or cascading the fault upstream — that's the standard domestic and light-commercial SCCR for final subcircuits in most European and IEC-60364 installations. The B-curve (3–5× In) is the go-to for resistive and general-purpose loads; don't use it for motor starting unless the inrush is well under 20 A (4 A × 5 = 20 A peak). Temperature derating is baked in: at 40 °C ambient the continuous rating drops to 3.84 A, at 45 °C it's 3.76 A, and at 55 °C it's 3.58 A. The 72 mm width (4 modular units) is standard DIN-rail footprint for a 4-pole MCB — it snaps onto the rail and occupies four 18 mm spaces. Mounting position is any, so you can lay it sideways in a shallow enclosure if needed.
Energy limitation class 3 — fast enough to limit let-through energy for downstream equipment protection. Sealable terminals allow the installer to lock the cover after commissioning.