M-pulse freehubs are precision machined and include the hub shell seal, pre-installed pawls with magnets, pawl retainer, freehub shield, double-row Enduro 3803 17x26x10mm bearing, Enduro 6802 15x24x5mm bearing, and freehub spacer. Compatible only with Shimano Micro Spline cassettes. Fits all M-pulse rear hubs. 

Not compatible with Shimano HG or SRAM XD/XDR cassettes. Not compatible with E-sync, Neo, Neo Ultimate, and 3.30 hubs.