This is a three piece adjustable floor guide with adjustable slide sections. It features a top, center mounted, adjustable, tandem roller assembly. The 1 in. flat nylon rollers are attached to a stamped steel tandem housing mounted on top of a 5/16 in. threaded steel rod. Used on Like closet doors 3/4 in. to 1-3/8 in. thick, it threads into a top bracket like Prime-Line part N 6797. Made of white nylon, the 7/8 in. tall guides. Universal design used by a variety of closet door manufacturers.