The Siemens SIRIUS 3RT1935-5AG61 is a magnet coil for Size S2 contactors, designed to replace the coil in a panel-mounted contactor when the original coil fails or the control voltage needs matching. It is a screw-terminal replacement part, not a standalone contactor — you swap it into the existing Size S2 frame. Rated for 100 V AC at 50 Hz and 110 V AC at 60 Hz, with an apparent power draw of 0.8 to 1.1 VA across that range. That is the holding power; pick-up inrush will be higher but the coil's thermal design handles it within the contactor's duty cycle.
Lifecycle reality — phased out, successor available
This part is flagged as a phased-out product. The official successor is the SIRIUS 3RT2 series coil — same Size S2 mechanical fit, same screw-terminal pattern, but the 3RT2 coil uses a different electrical design. Verify the control voltage and mounting interface against the 3RT2 datasheet before ordering the replacement.