Patio Door Roller

I'm afraid we can't identify your roller based on this photo. What you're showing here is only the interior casing of a complete roller assembly. The outer casing is missing, presumably still in the door. I'll need to see the whole assembly put together in order to ID a match. Please let me know if that would be possible.

I also suggest taking measurements of the outer casing when you take it out. You ill need precise, written dimensions for the sake of comparison in case there are multiple, similar options.