It's a 3-pole breaker rated for a continuous current of 100 A at 40 °C, and it holds that rating all the way up to 50 °C — only starts derating at 55 °C (96 A) down to 90 A at 70 °C. That thermal stability matters if this lives in a warm enclosure next to drives or transformers. The breaking capacity is the headline number here: 187 kA at 240 V, 121 kA at 415/440 V, 75.6 kA at 500 V, and 17 kA at 690 V.
The 4 auxiliary switches (HQ type) give you status feedback for PLC inputs or status lamps without needing a separate contactor block. Maximum power dissipation is 75 W at rated load — plan for that heat in the enclosure thermal calculation.