The Siemens SIRIUS 3RT5934-5AM01 is a replacement magnet coil for Size S2 contactors in the SIRIUS family. It's the service part you order when the original coil in a Size S2 contactor opens or shorts — not a complete contactor, just the coil assembly. Rated at 220 V AC at 50 Hz, with a voltage tolerance of 0.8... 1.1 times the rated value, meaning the coil holds in reliably between roughly 176 V and 242 V AC. That tolerance band is standard for SIRIUS AC coils; below 0.8 pu the contactor drops out, above 1.1 pu you risk overheating the winding.
This coil snaps into the Size S2 contactor frame — no DIN-rail mounting of its own, it's an internal component. When replacing the coil, verify the contactor frame size is S2; the coil won't physically fit S0 or S00 frames. The control supply is AC only, so don't feed it DC — the impedance and magnetic circuit are wound for sinusoidal AC, and DC will pull higher current and burn the coil.