The Siemens 5SL6205-7 is a SENTRON miniature circuit breaker (MCB) — 2-pole, C-curve, rated 0.5 A at 400 V AC, with a 6 kA breaking capacity per both IEC/EN 60898 and IEC 60947-2. That 6 kA rating is the same under both standards, so it's the figure you use for selectivity studies on a 400 V distribution board. The C-curve means it trips between 5 and 10 times rated current — standard for general-purpose lighting and small motor circuits where inrush isn't extreme.
Panel fit and derating
Two modular-width units (36 mm) on a standard DIN rail. Depth is 76 mm, installation depth 70 mm. Mounting position is unrestricted.