The Siemens 5SJ4263-7HG41 is a SENTRON 5SJ4 miniature circuit breaker (MCB) rated 63 A at 40 °C with a C-curve trip characteristic, 2 poles, and a 10 kA breaking capacity per EN 60898.
Rated 63 A continuously at 30 °C and 40 °C. Derates to 61.7 A at 45 °C, 60.4 A at 50 °C, 59.1 A at 55 °C, and 58 A at 60 °C. For a panel running at 50 °C ambient, expect a usable continuous current of 60.4 A — roughly 4% headroom loss from the nameplate. The DC rating maxes at 60 V, so it can serve DC branch circuits up to that voltage, but the 10 kA breaking capacity is specified per EN 60898 (AC).