This is a Zipp Speed Weaponry Freehub Body compatible with 2013-15 Zipp 188 hubs. Features: Not intended to convert older 10-speed freehub wheels to 11-speed freehub wheels Only intended to swap freehub compatibility (SRAM/Shimano - Campagnolo) with current 11-speed wheels 10 to 11-speed wheel conversion can only be completed by an authorized Zipp Service Center Includes cassette spacer Specifications: Freehub Body: SRAM/Shimano 11sp Hub Compatibility: Zipp 188 (2013-25) Material: Aluminum