not_applicable Used by a variety of sliding patio door manufacturers When the corner screw passes through the F-tab the assembly is captured by the side stile and bottom rail as the screw draws the two sides together 1-1/8 inch diameter tandem concave rollers Stamped steel with steel ball bearing Rear adjustment screw Allows the door to roll smoothly A Phillips head screwdriver is required for installation Please refer to the line art drawing for dimensions and compare with your needs before ordering