It's rated 37 kW at 500 V and 18.6 kW at 690 V under AC-3 duty — the motor-switching curve that matters for most conveyor, pump, and fan applications.
The main circuit uses screw-type terminals; solid wire accepts 2x (0.5 to 1.5 mm²) or 2x (0.75 to 2.5 mm²), and stranded goes up to 2x (10 to 50 mm²). That stranded range covers the main power feed for a 37 kW motor at 500 V — no need for lug adapters on the line side.
The AC-3 rating of 37 kW at 500 V is the headline number for motor switching — it tells you this contactor can handle a 37 kW induction motor on a 500 V line without welding contacts during normal starts. The AC-4 rating of 55 A at 400 V is the tougher duty cycle for reversing or jogging; if your application does frequent plugging, that 55 A figure is the one to size against, not the AC-3 kW number.