Johnson Universal Pocket Door Frame Set. Machine turned and balanced nylon, factory greased wheel. Split jamb and stud wood uprights have full steel sides and backs, removable track with keyhole slots and convex rail design, tricycle hanger, self-adjusting floor anchors and marked for cutting to smaller sizes. Rust resistant zinc plated steel. Extruded aluminum I-Beam track with mill-aluminum finish. Spruce, pine or fir frame header.