The coil pulls 24 V DC nominal; at that voltage the main contacts are rated 10 A, and at 400 V AC they handle 3 A.
The 10 A rating at 24 V DC covers the kind of DC loads you see in battery-backed or low-voltage control circuits — solenoid valves, small DC motors, signal lamps. Storage range goes -55 to +80 °C, which is what matters when the spare sits on a shelf in a warehouse that freezes in winter.
The contactor accepts solid or stranded wire: 2x (0.5 to 1.5 mm²) or 2x (0.75 to 2.5 mm²) per terminal. Coil connections are screw-type terminals, same as the main and auxiliary contacts — one screwdriver size for the whole job. Clearance around the unit: 50 mm above and below, 10 mm to the sides, 0 mm front and back.