Description: Made of qualified aluminum alloy; wear resistance, strong tensile strength Corrosion and rust resistance, high strength and sturdy It is used to mount single chain wheel because the double chain wheel screws is too long to lock by wrench Suitable for bike headset, stem, and chain wheel changing Inner Diameter: 10mm/4inch; Outer Diameter: 12mm/5inch; Thickness: 2mm Specification: Material: Aluminum Alloy Inner Diameter: Approx.10 mm / 0.39 inch Outer Diameter: 12mm/0.47 inch Thickness: Approx. 2mm / 0.08inch Package Includes: 10 Bike Washers Note: Please allow slightly difference due to manual measurement. Thanks
