The Schneider Electric A9N60746 is a 1-pole Acti9 C120N miniature circuit-breaker with a D tripping curve, rated 100 A at 40 °C. It clips onto a 35 mm symmetrical DIN rail — standard panel fit for distribution boards and sub-distribution in commercial or light industrial builds. That 100 A rating on a single pole handles a heavy feeder or a large submain. Breaking capacity hits 10 kA Icu at 230–400 V AC 50/60 Hz per EN/IEC 60947-2 — enough for most distribution panels behind a transformer. On the DC side it clears 15 kA at 125 V DC and 15 kA at 12 V DC, so it works in DC sub-distribution too.
For a BOM line that needs a 100 A D-curve MCB, this is the direct fit.
The thermal-magnetic trip unit gives you both overload protection (thermal bimetal) and short-circuit protection (magnetic coil). With a magnetic threshold of 12 x In, expect the instantaneous trip around 1200 A — that's deliberately high to ride through motor starting. Terminals accept up to 50 mm² rigid or 35 mm² flexible — big enough for the 100 A feed. The IP20 finger-safe enclosure is standard for panel-mount, not for wet locations.