The Siemens SIRIUS 3RT1934-5BG41 is a 125 V DC magnet coil designed for Size S2 contactors in the SIRIUS platform. It uses a screw terminal connection and is the replacement coil for contactors in that frame size.
The 125 V DC control voltage is the coil's rated operating voltage — apply this across the A1-A2 terminals to pick the contactor. The screw terminal connection matches the existing Size S2 contactor base; no adapter or rewiring of the control circuit is needed if the panel was originally built for a 125 V DC coil. The coil itself is the magnet assembly that pulls the contactor armature in; it is not a standalone contactor.
Mounts directly onto the Size S2 SIRIUS contactor via the standard snap-on interface. No DIN-rail space consumed beyond the contactor itself. Verify coil suppression polarity if the existing panel uses a free-wheel diode; the 3RT1934-5BG41 does not include a built-in suppressor.