It ships with three 3RT2015-2AB01 contactors and the RS assembly kit 3RA2913-2BB2 already integrated, so the line-up and interlocking are done — mount it and wire the power and control circuits.
The 5.5 kW at 400 V rating (AC-3 motor duty) tells you this assembly switches a standard 3-phase induction motor up to that load. The same assembly also carries 7.2 kW at 500 V and 9.2 kW at 690 V, so on a 690 V line it handles a bigger motor — but the contactor sizing and thermal overload relay (not included) must be coordinated for the actual motor FLA. The spring-loaded terminals on both main and control circuits accept 2x (0.5 to 4 mm²) solid or 2x (0.5 to 2.5 mm²) stranded, so no ring lugs needed; strip and push.
Physical footprint: 84 mm high, 135 mm wide, 145 mm deep. Clearance around the assembly: 6 mm upwards, forwards, downwards, and to the side; 0 mm backwards (flush to the rail). That keeps the panel layout tight.