The Siemens 5SL4325-8CC is a 3-pole miniature circuit breaker from the SENTRON 5SL family, rated 25 A at 400 V AC with a D tripping curve and 10 kA breaking capacity per EN 60898.
The 25 A continuous rating governs the maximum load current the breaker carries without opening — size your downstream conductors and load for this, not higher. The 10 kA breaking capacity per EN 60898 tells you the breaker can safely interrupt a fault current up to 10,000 A at 400 V AC — if your available fault current exceeds that, you need an upstream current-limiting device or a higher-rated breaker.
The breaker measures 90 mm high, 54 mm wide (3 width units), and 76 mm deep. Installation depth is 70 mm. Terminals accept 0.75 mm² to 25 mm² conductors.