The Siemens 5SV4312-0MB is a 2-pole residual current circuit breaker (RCCB) from the SENTRON family, Type AC, rated 25 A with 30 mA sensitivity at 230 V AC, 60 Hz.
That 10 kA figure is the conditional rated short-circuit current (IΔn = 0.5 kA per IEC 61008-1), which means the RCCB is backed by a series fuse rated max 63 A to handle fault currents above its own breaking capacity.
The 70 mm depth fits standard 60 mm grid-spaced distribution boards. IP20 with connected conductors, so it needs an enclosure or distribution board cover for finger-safe operation.