Drawout mounting means the power contacts slide in and out of a fixed cradle — you swap the chassis without disturbing the line-side wiring, which matters for planned maintenance windows in a motor control center.
Footprint is 322 mm high by 288 mm wide by 277 mm deep. That depth (277 mm) is the dimension behind the panel face — verify your enclosure depth before cutting the mounting plate. Above 40 °C ambient, apply the standard IEC 60947 derating curve — roughly 1 % per °C over 40, but the exact factor depends on enclosure ventilation. For a motor feeder, 800 A covers a 500 kW low-voltage motor at 400 V, or a 600 kW machine at 690 V, assuming typical full-load current.