The Siemens SENTRON 5SV3642-4 is a 4-pole residual current circuit breaker (RCCB), Type B, short-time delayed, rated 25 A with a 300 mA residual operating current at Un AC 400 V. Type B detection means it trips on AC, pulsating DC, and smooth DC fault currents — the full spectrum you get from variable-speed drives, UPS systems, or PV inverters. The short-time delayed design (SIGRES function) lets it ride through transient earth faults that would nuisance-trip a standard RCCB, so it belongs on circuits feeding equipment with inherent leakage, like motor drives or industrial power supplies. The 0.8 kA rated conditional short-circuit current (IΔn) is the maximum prospective fault current the RCCB can withstand when backed by a 100 A gG fuse. In a panel, that fuse limit tells the designer what maximum series overcurrent device the RCCB expects upstream.
The 60 mm grid spacing matches standard distribution board cutouts. IP20 with connected conductors in an installed distribution board; that's the usual touch-protection rating for enclosed panel gear, not a washdown rating.