What this breaker does on the line
The K curve sits between the standard C curve (general-purpose) and the D curve (high-inrush motor circuits), so it holds through a healthy magnetizing surge without nuisance tripping, but still clears fast on a hard fault.
Snaps onto standard DIN rail — the same profile as every other S200-series MCB in the panel. No special adapter or backplate needed. The 3-pole body takes up three modular units (17.5 mm per pole) on the rail, so it replaces an existing 63 A K-curve breaker or slots into a new build without re-spacing the busbars.