The Siemens 3RT5935-5AQ01 is a SIRIUS magnet coil, the replaceable solenoid that pulls in and holds a contactor's main contacts. It's the part that actually converts the control voltage into magnetic force — when it fails, the contactor stops closing.
Rated at 110 V AC, 50/60 Hz — that is the control voltage the coil sees, not the motor voltage. The operating range at 50 Hz is 0.8 to 1.1 times the rated voltage, so on a 110 V nominal system the coil will pick up and hold anywhere from about 88 V to 121 V. That's a standard tolerance for AC coils in the SIRIUS line; it means you don't need a perfectly regulated control transformer, but you do need to stay inside that window. Below 88 V it may chatter or drop out, which burns the coil and leaves the load floating.