Mantel Floating Wall Shelf, 48"W, WHITE Extra small: 1.5"H x 12"W x 4.5"D. Small: 1.5"H x 24"W x 4.5"D. Medium: 1.5"H x 36"W x 4.5"D. Extra large: 1.5"H x 60"W x 4.5"D.