Usage Tips:Freehub Body: 12 Speed hub Planetary Ratchet Micro Flywheel. This is designed with a ratchet system and includes two bearings for smooth operation.Flywheel: The Freehub Body features a 12 speed flywheel with Micro technology, ensuring high performance and durability.Craftsmanship & Material: The freehub body is made from 7075 aluminum alloy with heat treatment, ensuring its strength and longevity. It's fully CNC machined and anodized for added durability.Weight & Dimensions: Weighing only 51.3g (including the sleeve), this lightweight freehub body has a hole diameter of 15mm, supporting both 12mm thru axle or 5mm quick release skewer.Ratchet & Toothed Rings: The ratchet can be 18/36/54/60T as per your needs while the toothed rings measures M34*1.0-26T. Specification: To determine if this freehub body is suitable for your hub:1) Check the specifications of the toothed ringd which should be 34 (outer diameter) *8 (height) mm-26 t.2) Ensure that your flywheel meets 12 speed specification.3) Confirm that the outer diameter of your hub axle is 15mm which corresponds to a thru axle rod of size 12mm. Package Includes: 1Freehub Body Note: Please allow slightly errors 1-2cm differences due to manual measurement.