Sliding glass door rollers

I'm afraid I can't identify what roller you might need from this photo. What you're showing me here is just the internal component of a complete assembly. The outer housing is missing, but is an essential component; it's probably still in the door.

We need to see the whole assembly removed and put together for reference. I also need you to take measurements of the outer housing and write them out in your response for us to review. Please be as precise as possible; a photo of a measuring implement will not be sufficient.