Prime-Line N 6790 Mirror Door Roller Assembly – Replacement Part for Steel-Framed Mirror Closet Doors, Steel Housing and FLAT Edge Plastic Wheel, 1-7/16 inch - Bi Fold Door Hardware - Amazon.com
N 6790 - Acme Mirrored Door Roller Assembly, 1-7/16 inch Flat Nylon Roller, 1 per package.
Top-Rolling Framed Bypass Door Hardware - Onward Hardware