Convert your R45D 6 Bolt Gen. 2 and R45D Centerlock hubs to fit Shimano HG11, HG12, Micro Spline, or SRAM XDR cassettes with our Gen 4 conversion kit. Gen 4 conversion kits include a pre-assembled axle, driveshell, and updated adjusting clamp for a plug and play swap. Installation requires a 2.5mm hex key and T10 Torx tool. - Compatible with R45D 6-Bolt Gen.2 hubs. Serial numbers will begin with 6910. - Compatible with all R45D Centerlock hubs. Serial numbers will begin with 6710. - 142x12mm axle. - Available with stainless steel or ceramic bearings. - Available in Silver or Black. - Please contact service@cosmicsports.de with any compatibility questions.