Prime-Line N 6848 Door Roller, 1 in Dia Roller, 1-1/4 in W Roller, Steel, 3-Roller, Top Center Mounting

N 6848 is a top, center mounted, adjustable, tricycle style roller assembly. The three 1 in flat durable nylon rollers provide a smooth, long-lasting quiet operation. They are attached to a stamped steel & nylon carriage mounted on top of a threaded steel rod. The threaded rod catches into a bracket that locks it in place. Used on Johnson Bi-pass & Pocket Closet Doors.