Casement window Parts for ROW casement windows
I recognize this nylon guide. I think it's from an old hinge set that's no longer made. We won't be able to supply this part but we could potentially supply a new hinge set that can work as a substitute. See our 36-048 and let me know what you think. We also have a video tutorial that shows you how these function.
The guide your image is pointing to here is a component on the entire hinge assembly. These are not sold separately and you won't be able to replace it by itself, so total hinge replacement is necessary. Our 36-048 comes with its own slide and is ready to install out of the box, just note that because it is so different from your old hinge that some retrofitting may be required. You will, at minimum, have to replace both the top and bottom hinges at the same time. Drilling new installation holes may also be necessary.