Prime-Line Products D 1551 Sliding Door Tandem Roller Assembly with 1-1/8-Inch Steel Ball Bearing (2) 1-1/8in. Tandem steel ball bearing rollers Used by Elco and other glass door manufacturers Housing dimensions: W: 11/16in. L: 3-1/8in. H: 1-3/32in. Overall thickness: 13/16in. Adjustable steel housing assembly