Prime-Line Products D 1756 Sliding Door Roller Assembly with 1-1/4-Inch Steel Ball Bearing Steel ball bearing roller assembly Fits on Window Master and other patio door manufacturer Housing dimensions: thickness, 9/16in. Length, 2-1/8in. Height, 1-7/16in. Steel ball bearing roller assembly Housing dimensions: thickness, 9/16in. Length, 2-1/8in. Height, 1-7/16in.