The Siemens 3RT2017-2WB41 is a SIRIUS coupling contactor in the S00 frame size — the smallest footprint in the SIRIUS contactor family, at 45 mm wide by 70 mm tall by 121 mm deep. It's designed for switching loads in control panels where you need galvanic isolation between the control circuit and the power circuit, often used as an interface between a PLC output and a motor starter or heater contactor. The 24 VDC coil pulls in at 85% of rated voltage (20.4 V) and drops out below that; the spring-type terminals accept solid or stranded wire from 0.5 to 4 mm², which is the standard range for control wiring in most panels.
The headline rating is 10 A at 24 VDC — that's the continuous current the main contacts can carry in DC-1 duty (resistive loads). If you're switching inductive DC loads (DC-3 or DC-5), you'll need to derate: at 48 V it's 2 A, at 110 V it's 1 A, at 220 V it's 0.3 A.
That's tight enough to pack several contactors side by side in a standard 600 mm wide enclosure without crowding.