Siemens 110 → 240 V ac/dc Safety Relay Single Channel with 4 Safety Contacts. SIL IEC 61508: 3. Range: SIRIUS. Reset Method: Automatic, Monitored. Terminal Type: Screw. Depth: 121.7mm. Width: 22.5mm. Length: 100mm. Series: 3SK1. MPN: 3SK1111-1AW20