Photos showing single roller was removed from one of the sliding glass door pane approx. 10 years ago.
Photos showing tandem rollers was the rollers used to replace the single roller.
The part shows DISCO 2136-1. There are approx. 24 door panes in need of replacement. They range from 5'x 8' to 3'x 6'8" each.
I am an architect and homeowner. I will have an experienced handyman replace the rollers. Thank you.