This is the part you'd reach for when protecting inductive or motor-starting loads where the inrush peak is higher than a standard C-curve can tolerate without nuisance trips.
What the Trip Curve K means on your panel
Curve K trips magnetically between 8 and 12 times rated current (In). For a 16 A breaker, that's a magnetic trip threshold of 128 A to 192 A. Compare that to a typical Curve C (5–10× In, or 80–160 A for a 16 A unit). The K curve gives you a wider window for high-inrush loads like transformers, solenoid valves, or small motors without the breaker opening on startup. The trade-off: it provides less protection against moderate overloads than a Curve Z or B — so you need to verify the downstream cable and load can handle the extra let-through.