The Schneider Electric A9N3P10CIN is a 3-pole miniature circuit breaker from the Acti9 xC60 series, rated 10 A with a C-curve trip characteristic. Breaking capacity is 10 kA at 380–415 V AC (50/60 Hz) and 15 kA at 100–125 V DC, both per IS/IEC 60947-2. That 10 kA AC rating is the standard for most sub-distribution boards; the DC rating is useful for control circuits or battery-backed loads.
The 54 mm width (6 x 9 mm pitches) and 77.5 mm depth fit neatly into a distribution enclosure;
Overvoltage category IV and pollution degree 3 mean it's rated for the main incoming supply in a building, not just downstream sub-circuits.