Three poles, rated 125 A continuous at 40 °C ambient, and it holds that same rating all the way up to 50 °C before it starts to derate: 122 A at 55 °C, 120 A at 60 °C, 117 A at 65 °C, 114 A at 70 °C. That's a solid thermal curve — you don't lose headroom until the panel is genuinely hot. The interrupting capacity is where this breaker earns its place in the panel. At 240 V it clears 187 kA; at 415 V it's still 121 kA; at 440 V it drops to 75.6 kA; at 500 V and 690 V it holds at 17 kA.
Panel fit and power loss
Footprint is 76.2 mm wide, 130 mm tall, 70 mm deep — a compact 3-pole MCCB that fits standard Siemens 3VA mounting plates and busbar systems.