9/16 inch Dome Hole Plug normally used to cover adjustment screw hole on sliding patio door rollers, one for each roller hole.
Used by Weather Shield on the Visions 2000 and Pro Shield sliding patio doors and by other manufactures.
Application: Hole Cover Cap
Inside Diameter: 9/16 inch (14.3mm) .562
Outside Cap Diameter: 11/16 inch (17.4mm) .687
Height: 3/8 inch (10.3mm) .41
Multiple Locking Steps for Panel Thickness up to .125 ̋ (3.2 mm)
Priced and sold each.