The Siemens 3RQ4118-1AB00 is an output coupler relay from the SIRIUS 3RQ4 family, built in the narrow 6.2 mm housing. It switches one change-over contact at a thermal current of 6 A, with a 24 V AC/DC coil.
The narrow pitch lets you pack more isolation points per linear meter of rail — roughly 160 relays per meter. That matters when a panel layout is tight and you need to separate control signals from the PLC output card.
