Features: Make from Titaniums Alloys materials, it have good mechanical property, toughly, and corrosions resistance. High hardness & tensile strength, low wear tear, Enduring & reliable use. Suitable for installing middle axles of bicycles square hole. Accurate and smooth tapping, chamfered entrance, easily installation. Suitable for installing the center axles of various bicycles, such as mountain bbicycles, foldings bicycles. Widely used in bicycles maintenance, modification, upgrading and other scenario. Specifications: Materials: Titaniums alloy Color: Titaniums/Gold/Colorful Size: as shown in the picture Package Includes: 1pc Screw note: Please allow 1-2cm errors due to manual measurement, make surely that you not mind before order. Due to difference between different monitors, the picture may not reflect the actual color.