One-piece design maximizes strength and reduces breakage. Chrome molybdenum alloy steel (Cr-Mo) for exceptional strength. Laser-etched sizes with color-coded rings for quick identification. EVA foam tool storage organizer. Manganese phosphate finish to resist corrosion. Sizes included: 1/4 in. x 9/32 in. x 5/16 in. x 3/8 in. x 7/16 in. x 1/2 in. x 9/16 in. x 5/8 in. x 11/16 in. x 3/4 in. "