Prime-Line Products D 1548 Sliding Door Dual Roller Assembly with 1-1/4-Inch Steel Ball Bearing 1-1/4in. O.D. Dual steel ball bearing center grooved rollers Housing dimensions: W: 1-9/16in. L: 2-1/4in. H: 1-3/16in. Adjustable steel housing assembly Fits Guaranteed Aluminum doors