Siemens SIRIUS 3RT1916-1PA2 is an EMC suppression module for Size S00 contactors.
This module snaps onto the front of a Size S00 SIRIUS contactor (such as the 3RT1016 series). It occupies the same DIN-rail footprint as the contactor itself, adding no extra width. The RC circuit connects across the coil terminals, so verify the coil voltage matches the module's 575 V AC rating. Wiring is straightforward: the module's two leads connect in parallel with the coil. No additional panel space is needed beyond what the contactor already occupies.