nylon roller and nylon housing assembly for small, sliding aluminum-framed window

Question

This is what the bottom of the window sash looks like.  It is supposed to have two of these nylon roller assemblies, but it only has one.

Tom · Accepted Answer

Thank you for your patience during this busy season. I'm afraid I don't recognize this roller. Would it be possible to see it out of the window? That may help us find a match.