Sliding glass door-guardian brand

We can help you ID this roller for sure, but what you're showing me here is just the internal portion of a larger roller assembly. There should be an external housing, probably still in the door. If you can show me that, I'm very confident I can tell you exactly what you need, or at least narrow it down to two or three options.

Don't worry about there not being any marks on your roller, those rarely help. The only thing that tells you what these are is their physical design, so that's what we gotta look at.