What the K-curve means for your load
K-curve breakers are built for inductive loads — transformers, solenoids, motor starters — where the inrush current can be several times the full-load rating. The K-curve holds the magnetic trip at 10–14× rated current (here 250–350 A instantaneous), so it won't nuisance-trip on transformer energization or coil pickup. That's the key difference from a B-curve (3–5×) or C-curve (5–10×) in the same S200MUC family. If your BOM line is protecting a 24 VDC control transformer or a bank of contactor coils, the K-curve is the right call.
Integration note
The 2-pole footprint occupies two module widths (roughly 36 mm). Terminals accept 0.5–25 mm² conductor; torque to 2.5 Nm. For DC circuits, observe polarity markings on the breaker — the S200MUC series is polarity-sensitive on DC, so wire the line side to the marked terminal. No auxiliary contact slot on this base model; if you need a remote trip indication, step to the S200MUC variant with the integrated auxiliary contact.