This solid aluminum CRL Crescent Style Back-to-Back Towel Bar has an arched appearance that lends style and elegance to any shower enclosure. Set of two for mounting on each side of the glass. Available in several stock finishes as well as custom finishes available upon request. Hole diameter required is 1/2 inch (12 millimeter). Center-to-Center Hole Spacing is 18 inches (457 millimeters) for the 18 inch Towel Bar, and 24 inches (610 millimeters) for the 24 inch Towel Bar.