The Siemens 3RT1935-5AL21 is a SIRIUS magnet coil designed for Size S2 contactors, rated at 230 V AC at both 50 Hz and 60 Hz with a screw terminal connection. This is a phased-out product; the official successor is the SIRIUS 3RT2 series.
The lifecycle stage is listed as current, but the manufacturer explicitly marks this as a phased-out product with the successor being the SIRIUS 3RT2 series. For BOM freeze or long-term support planning, the 3RT2 series is the drop-in replacement path to quote against.
This coil mounts onto SIRIUS Size S2 contactors via screw terminals. The 230 V AC control supply voltage operates at both 50 Hz and 60 Hz, so it fits panels specified for either mains frequency without a coil swap. The operating range at 50 Hz is 0.8 to 1.1 times the rated voltage, meaning the coil holds in reliably down to about 184 V and up to 253 V at the terminals.