The C25N4TM250C is a Schneider Electric ComPacT NSX250N moulded-case circuit breaker, 4-pole, rated 250 A at 50 °C with a thermal-magnetic TM-D trip unit. That 50 kA figure is the interrupting rating you need for high-fault-capacity panels; the breaker also carries 90 kA Icu at 240 V and 36 kA at 500 V, so it coordinates with upstream gear across a range of system voltages. The TM-D trip unit provides fixed thermal (overload) and fixed magnetic (short-circuit) protection — L and I curves, respectively — with no interchangeable rating plugs. That means the 250 A setting is permanent; if your load calculation calls for a different frame, this is not the breaker to re-spec.
Backplate-mounted, 140 mm wide, 161 mm high, 86 mm deep. Front-connected both upside and downside. Horizontal or vertical mounting is permitted; flat on the backplate. Five accessory slots available for auxiliary contacts, shunt trips, or under-voltage releases.