The Schneider Electric A9F68404 is an Acti9 iT60 miniature circuit breaker (MCB) rated at 4 A with a C-curve trip characteristic, 4 poles, and a 72 mm width on a DIN rail mount.
Breaking capacity — what the 50 kA rating means for your panel
This MCB carries a 50 kA Icu at 220…240 V AC and 380…415 V AC per EN/IEC 60947-2, and 25 kA Icu at 440 V AC. At 400 V AC it also meets 10 kA Icn per EN/IEC 60898-1. The C-curve (8 x In ±20 % magnetic trip) gives a 32 A instantaneous pickup, so it rides through inrush from small motors or capacitive loads without nuisance tripping.
Snap-on DIN rail mount, 72 mm wide (8 x 9 mm pitches). Terminals accept 1…25 mm² rigid or 1…16 mm² flexible copper, with a 14 mm strip length and 2 N.m tightening torque. The removable comb busbar is pre-installed, so daisy-chaining phases across multiple MCBs in a row is straightforward — no extra busbar kit needed. IP20 finger-safe terminals, but the front face is not sealed; keep it inside a panel with a door.