Siemens SENTRON 5SQ3270-1BA20 — 20 A C-Curve MCB, 1P+N
Breaking capacity is rated at 3 kA per EN 60898 and 4.5 kA per IEC 60947-2. That 4.5 kA figure under the industrial standard means this MCB can safely interrupt a fault up to 4.5 kA at 240 V AC without welding its contacts or rupturing the housing — sufficient for most sub-distribution boards fed from a transformer of 250 kVA or less.
Neutral conductor switching is integrated, so you don't need a separate neutral bar or link for the switched neutral; the 1P+N design handles it inside the breaker housing.