The Schneider Electric A9F06440 is an Acti9 iC60H miniature circuit breaker, 40 A rated current, B curve, 4 poles.
The A9F06440 delivers 42 kA Icu at 12-133 V AC, 30 kA at 220-240 V, 15 kA at 380-415 V, and 10 kA at 440 V — all per EN/IEC 60947-2. Under the 60898-1 standard it's rated 15 kA Icn at 400 V. The 15 kA at 400 V covers most European industrial mains. The B curve magnetic trip triggers at 4 x In +/- 20 %, so it's sized for resistive and lighting loads where inrush stays moderate — not motor starting.
Snaps onto DIN rail, 72 mm wide (9 x 8 mm pitches), 91 mm tall, 78.5 mm deep. IP20 finger-safe front. Terminals accept 1-35 mm² rigid or 1-25 mm² flexible, double terminal top and bottom — useful for looping feed-through without a separate distribution block. Pollution degree 3 rated, so it's fine in a typical industrial panel without sealed enclosures.
The Acti9 iC60H family is Schneider's mainstream MCB platform; replacements and spares are stable.