What you're looking at
The 80 A rating holds at 45 °C and 50 °C; it derates to 74 A at 70 °C. That thermal curve matters if you're packing this into a hot enclosure — the 6 A drop between 50 °C and 70 °C is real headroom you lose.
Breaking capacity — what it handles
This MCCB clears 52.5 kA at 240 V, 32 kA at 415 V, 13.6 kA at 440 V, and 7.5 kA at both 500 V and 690 V. At 690 V the 7.5 kA still covers most industrial motor branch circuits.
Fit and footprint
Dimensions: 130 mm tall, 101.6 mm wide, 70 mm deep. Power loss is 19.2 W maximum at rated current. That's moderate for an 80 A 4-pole — factor it into your enclosure thermal calc if you're stacking several breakers side by side.