50.60.00.211 ENCORE LH DYAD OPERATOR was the type that they said replaced the one I had. it seems to match the one that you have Product Code: 39-220B the measurements seem to match the down-offset link arm measures at 4-7/8" overall if this is the length after the elbow that attaches to the window.
This window is in a shower area and the operator has to be watertight.
