The 200WG Sliding-Glass Door Hardware features an extruded aluminum I-beam track that surface-mounts directly to the wall and can support a frameless glass door. Side-mount hangers support ½-inch-thick tempered glass doors up to 400 pounds. Each four-wheel hanger is also equipped with nylon-encapsulated, permanently sealed ball bearings. It comes in single-door openings from 2 to 4 feet and double-door sets to fit openings 4 to 8 feet wide.