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: 6, 7, 8, 10, 12, 14, 15, 17, 18, 19 mm "