The screw-type terminals on the main circuit accept 2x 0.75 to 2.5 mm² solid or stranded wire, or 2x 4 mm². Breaking capacity is the headline here: 100 kA at 240 V, 400 V, and 500 V, dropping to 4 kA at 690 V. The gL/gG fuse-limit ratings (50 A at 400 V, 40 A at 500 V, 35 A at 690 V) tell you the maximum upstream fuse that still lets the breaker coordinate properly.
Panel fit and clearances
Footprint is 45 mm wide by 97 mm deep by 97 mm tall — a standard 45 mm module width that matches most SIRIUS contactor and overload relay companions. Clearance requirements: 50 mm upwards and downwards, 30 mm to the side, zero forwards and backwards. That zero forward clearance means you can butt it against a panel door or another device without derating, as long as the side and vertical gaps are respected.