The Schneider Electric A9K23240 is an Acti9 iK60N miniature circuit breaker (MCB) rated 40 A at 30 °C, 2 poles, with a B tripping curve. The 6 kA Icn at 400 V AC (EN/IEC 60898-1) is the rated short-circuit breaking capacity: it can safely interrupt a fault up to 6,000 A without welding or failing open.
At 36 mm wide (4 x 9 mm pitches), it occupies two standard module spaces in a distribution board. The tunnel terminals accept 1–35 mm² rigid or 1–25 mm² flexible cable; tighten to 3.5 N·m. IP20 finger-safe front, so it is intended for enclosed panels or consumer units — not outdoor or washdown locations.