The Siemens SIRIUS 3RT1325-3XF48-0LA3 is a size S0 power contactor with four normally-open main contacts, rated at 7.5 kW for AC-2 duty at 400 V — that's the motor-switching rating for slip-ring or wound-rotor motors, where the load current stays high through the opening arc. The 110 V DC coil includes a built-in varistor surge suppressor, so you don't need to add an external snubber on the coil circuit.
The 7.5 kW AC-2 at 400 V rating governs the real motor load this contactor can switch — AC-2 is the category for starting and plugging of slip-ring motors, where the contactor must interrupt the rotor current at standstill. For AC-12 resistive loads (heater, lighting) it's rated at 10 A maximum. Type 1 coordination allows up to 63 A. That's the fuse sizing you need to protect the contactor during a bolted fault — Type 2 means the contactor remains usable after clearing the fault, Type 1 means it may need replacement. The contactor mounts on a 35 mm DIN rail per EN 50022, either screw-fixed or snap-on, and fits a standard S0 footprint — 71 mm wide, 119 mm high, 101 mm deep. The main circuit terminals are screw-type, accepting up to 2x 10 mm² or 1x AWG 12 solid/stranded — the wire range is 0.25 to 2.5 mm² for the auxiliary contacts (2x conductors).