This is a side mounted, top hung, adjustable wardrobe door roller assembly with a single 7/8 in. grooved nylon wheel for the back door panel. The stamped steel bracket assembly is adjustable and has a 9/16 in. offset. It fits 3/4 in. to 1-3/8 in. thick doors. Used on old Style Kenna-Frame closet door systems. For the front door panel use Prime-Line part N 6717.