The Siemens 5SL4205-7 is a SENTRON miniature circuit breaker — 2-pole, C-curve, rated 0.5 A at 400 V AC, with a 10 kA breaking capacity per both IEC 60898 and IEC 60947-2.
The C-curve (tripping characteristic class C) means the magnetic trip fires at 5 to 10 times rated current — so for a 0.5 A breaker, instantaneous trip occurs between 2.5 A and 5 A. At 30 °C it carries the full 0.5 A; at 40 °C it derates to 0.47 A, at 45 °C to 0.46 A, and at 55 °C to 0.43 A — so if the panel runs hot, factor that derating into the load calculation. Mounting position is any — no orientation restrictions.