The D curve means the magnetic trip fires between 10 and 14 times the rated current (60 to 84 A), so this breaker is sized for loads with a high inrush, like small motors, transformers, or lighting ballasts that would nuisance-trip a B or C curve. The 6 kA breaking capacity at 230 V AC (per EN/IEC 60898-1) covers most final-subcircuit fault levels in standard domestic and commercial installations; if your prospective short-circuit current exceeds that, you'd step up to a higher-rated upstream device or move to an industrial-pattern MCB.
Clip-on mounting to DIN rail, 18 mm width (2 x 9 mm pitches). Tunnel-type terminals accept 0.75…16 mm² rigid or 0.33…10 mm² flexible upstream and downstream. The neutral is on the left, toggle control on the protected pole.