1、One-piece molding, hollow design on the inner wall, denser output power and high rotation efficiency. 2、High-quality alloy steel, nice low temperature impact, strong toughness, nice fatigue resistance. 3、It is suitable for X1600, X1700, 1501 wheel and 190, 240S, 340, 350, 440,540 hub. 4、Perfect repairing accessories for bicycle hubs, and can be a nice replacement for old or damaged ones. 5、Delivery includes a storage box, the kits are easy to carry. Features: One-piece molding, hollow design on the inner wall, denser output power and high rotation efficiency. High-quality alloy steel, nice low temperature impact, strong toughness, nice fatigue resistance. It is suitable for X1600, X1700, 1501 wheel and 190, 240S, 340, 350, 440,540 hub. Perfect repairing accessories for bicycle hubs, and can be a nice replacement for old or damaged ones. Delivery includes a storage box, the kits are easy to carry. Specifications: Material: 20CRMOTI(Alloy Steel) Angle: 6° Center Hardness: ≥HRC55 Surface Hardness:≥HV2000 Limit Torque:≥400NM Fatigue Resistance: ≥100,000 Times(250NM) Ratchet Size: 27.5 * 27.5 * 11mm/ 1.1 * 1.1 * 0.4in Package Size: 90 * 60 * 20mm/ 3.5 * 2.4 * 0.8in Package Weight: 61g/ 2.2oz Packing List: 2 * Star Ratchet 1 * Ratchet Cover 2 * Coil Spring 1 * Storage Box 2 * Star Ratchet 1 * Ratchet Cover 2 * Coil Spring 1 * Storage Box