Description: 12 Speed Systems: The flywheel lock cover is specifically designed for M7100, M6100, and M8100 series, ensuring seamless integration and optimal performanceLightweight and : Crafted from high strength aluminum alloy, this cassette lockring offers a great balance of lightweight design and sturdy durability, ensuring long term performance without adding unnecessary weight to your bikeAnti Slip Design: This flywheel cover caste lockring maintains its integrity in various weather conditions. The anti slip texture provides a grip during installation and removalCompact Dimensions for Easy Handling: With dimensions of 3.2 cmx1.3 cm/1.26 inchx0.51 inch, this bicycle flywheel cover is compact yet effective, making it easy to handle during installation while providing a secure fit on your bike's Complete Package: Each package includes 1 flywheel lockring, great for repairing or maintenance replacement part Specification: Material:Aluminum Alloy Size Chart: 3.2 cmx1.3 cm/1.26 inchx0.51 inch Package Includes: 1 Bicycle Flywheel Cover Note: Please allow slightly errors 1-2cm differences due to manual measurement.