Be In Your Mind 10PCS Bicycle Chainring Bolt Spacers Washer Aluminum Alloy Double Ring to Single Gasket for Bike Headset Chainwheel 1mm Thickness 10mm Inner Diameter

These bicycle chainring bolt spacers are made of aluminum alloy, wear-resistance, strong tensile strength, rust resistance, high strength and sturdy. It is used for mounting single chain wheels as the double chain wheel bolts are too long to lock with a wrench. Fit for bicycle headset, stem and chain wheel change. Fine tune the chainring to get the perfect chain alignment. The internal diameter is 10mm/ 0.39inch, external diameter is 12mm/ 0.47inch, thickness is 1mm/ 0.04inch. Package includes 10 pieces of bike chain wheel washers.