Tension Roller for Patio Screen Door

I have been trying to find a good match to my screen door's rollers but have been unable to. I have gone to Home Depot and Lowes trying to find a generic roller but none fit the door and will work with it. On line hunting has been fruitless as of now. There are no major markings on the door glass sliding door to show the make or model of the assembly making it hard to figure out where I can turn, if not he manufacturer, for replacement rollers. Let me know what other information other than the pictures that you would need to guide me to a good match.