The 4.5 kA breaking capacity per EN 60898 tells you it can safely interrupt a fault current up to that level; for most building infrastructure circuits this is adequate, but check your available fault current at the panel — if it exceeds 4.5 kA, step up to a higher-rated series.
The 1+N-pole design switches both phase and neutral, with the neutral pole switching as well — important for circuits where you need full isolation on both conductors. One modular width unit (18 mm) per pole keeps the panel fill factor tight.