It's a current-production part, so it's still a standard BOM line item, not a scavenger hunt. The 55 mm width is the S2 footprint — plan your DIN rail fill accordingly.
Rated 18.5 kW at 500 V AC-3 — that's the motor-switching duty for a typical 25 HP induction motor on a 480 V line. For heavy-duty jogging or plugging, the AC-4 rating is 29 A at 400 V. That's the figure to watch if your application involves inching or reversing under load — AC-3 won't cover that duty cycle. The auxiliary contact block is rated 10 A at 24 V, 6 A at 230 V, and 3 A at 400 V. These are the limits for your control-circuit interlocking; don't parallel them to exceed the package limit.
Main circuit terminals are screw-type, accepting 2x (0.75...25 mm²) stranded or 2x (0.25...2.5 mm²) solid. That's enough for a 16 mm² feed at 40 °C ambient — common for a 25 HP motor circuit. IP20 on the front, IP00 at the terminals. The terminal area is live when the contactor is wired, so keep it inside an enclosure with a door interlock or at least a warning label.
RoHS compliance date is noted as May 1, 2012, so it meets the EU directive. Expect a CE declaration and manufacturer's declaration of conformity with the shipment; UL/CSA marks are typical for the SIRIUS line but not confirmed in this specific variant's evidence.