5 Pieces Bike bottom bracket gasket O-ring flywheel washer spacer built in aluminum alloy to ensure lasting results, which is very durable, heat resistant, oil resistant, anti-corrosive. The exquisite workmanship and convenient to install and remove, it is perfect to get a good fit on your bike. Perfect for adjusting the bottom bracket, steering wheel or bicycle hub, its washers will never accumulate dust or rot by oxidation 5 different sizes (1/1.5/2/2.5/3mm) for your demand, meets different needs and ensure your bike is attractive. Great for adjusting your bike bottom bracket, flywheel or hub, can be applied to the BB axle as well. Specification: Material: aluminum alloy Outer Diameter: 42mm/ 1.65 inch Inner Diameter: 35mm/1.37 inch Thickess: 1mm/1.5mm/2mm/2.5mm/3mm Package Includes: 5 Pieces Bike bottom bracket gaskets