It carries a continuous current of 1000 A at 40 °C and delivers a 187 kA interrupting capacity at 240 V AC — that figure drops to 121 kA at 415 V and 440 V, 75.6 kA at 500 V, and 52.5 kA at 690 V, so the voltage class of your system directly governs the fault-clearing margin. The overcurrent release is a TM240 thermal-magnetic type, sized for the 1000 A frame.
The 1000 A rating holds at 40, 45, and 50 °C ambient. Above that, the continuous current must be reduced: 960 A at 55 °C, 940 A at 60 °C, 920 A at 65 °C, and 900 A at 70 °C. Physical envelope: 320 mm high, 210 mm wide, 120 mm deep. That depth is the key dimension for enclosure depth — verify your gland plate and rear bus clearance against the 120 mm figure before committing the panel layout.