Durable aluminum. Polished, smooth aluminum finish. Covers seam or gap between 2 flooring surfaces of unequal height. Protects carpet edge from fraying and provides clean edge where low-medium pile carpet meets other flooring types. 1-3/8" wide. Available in 3' and 6' lengths. Fasteners provided. Carpet metal installation on concrete surface suggestion: Drill a hole in the concrete, insert a 3/16" x 1-1/4" or 1/4" x 1-1/4" wood dowel. Use the screw nails provided with carpet metals, insert into dowel, expanding the dowel to lock in place.