New MicroSpline freehub design allows the use of 10 tooth cogs as part of the new 12sp cassettes without the risk of damage to the cassette body. MicroSpine freehubs feature Shimano`s Scylence system which is constructed of two plates that completely separate when freewheeling which eliminates the standard ratcheting sound from coasting entirely. 7.6 degrees of engagement. **SHIMANO HUBS ONLY AVAILABLE FOR WHEELS BUILDS**