Safety relays, ReLy, RLY3-OSSD400, Applications: Output expansion module for OSSDs, Compatible sensor types: Safety sensors with OSSDs, Connection type: Front connector with spring terminals, Restart interlock: no, External device monitoring (EDM): Via path, Outputs: 4 enabling current paths (safe), 1 feedback current path (for use as external device monitoring, not safe), 1 signaling current path (not safe), Housing width: 28 mm