The Siemens 3RH2911-2DE11-Z W97 is a lateral auxiliary switch block designed for the 3RT2.1 contactor series. It provides one normally-open and one normally-closed contact on each side — left side carries 41/42 (NC) and 53/54 (NO), right side carries 23/24 (NO) and 31/32 (NC) — for a total of two NO and two NC contacts across the block. The solid-state-compatible designation means the contacts are engineered for low-energy switching, so they handle the leakage currents and dry-circuit conditions common with PLC outputs and solid-state relays without welding or failing to make contact.
Mounts directly onto the left or right side of a 3RT2.1 contactor, snapping into the auxiliary contact slot. The 70 x 68 x 20 mm package fits within the standard contactor envelope, so it doesn't increase the DIN-rail footprint beyond the contactor itself.