The MGN60909 is a C60N miniature circuit-breaker from the Multi9 range, a 4-pole unit rated 25 A at 50 °C with a C curve and 20 kA Icu at 240 V AC. The C curve (magnetic trip at 8.5 x In ±20%) is the standard for general-purpose distribution and small transformer loads; it won't nuisance-trip on moderate inrush the way a B curve would, but it's faster than a D curve for motor starting.
The Ics (service breaking capacity) at that same voltage is 15 kA, or 75% of Icu, meaning after clearing a 15 kA fault it's still usable, not a one-shot part. At 415 V AC the Icu drops to 10 kA, and at 440 V AC to 6 kA. The 4.5 kA Ics at 440 V AC is the figure to check for 400 V three-phase distribution.
Snaps onto 35 mm symmetrical DIN rail — standard for any European-style panel. The 4-pole body takes 8 module pitches (72 mm wide), so plan for that footprint in your enclosure layout. IP20 rated, so it's for inside a closed panel only — no washdown exposure. The toggle gives local ON/OFF indication, and a contact position indicator confirms isolation status (it's suitability-for-isolation certified per EN/IEC 60947-2).