Mantel Narrow Floating Wall Shelf, 36"W, BLACK Extra small: 1.5"H x 12"W x 2.5"D. Small: 1.5"H x 24"W x 2.5"D. Medium: 1.5"H x 36"W x 2.5"D. Extra large: 1.5"H x 60"W x 2.5"D.