Product Description Zipp ZM900 End Cap Set for Rear Hub with XD or Micro Spline Freehub These end caps are compatible with the Zipp ZM900 rear hub with a Boost installation width of 12 x 148 mm. It includes one cap for the left side and one for the right side, where the latter is compatible with either SRAM XD or Shimano Micro Spline freehubs, depending on the version. The ZM900 Disc 6-bolt hub is used in the 1ZERO HiTOP S MTB wheelset. Compatibility:ZM900 rear hub1ZERO HiTOP S rear wheelManufacturer Numbers:SRAM XD:11.2028.062.006Shimano Micro Spline:11.2028.062.005Contents:1 pair of Manufacturer: SRAM LLC 1000 W. Fulton Market 4th Floor Chicago IL 60607 USA info@sram.com Distributor: SRAM Europe Sales and Services B.V. Paasbosweg 16 3862 ZS Nijkerk Netherlands info@sram.com