ZIPP Freehub for 2013 - Current 188 Hub 11-speed SRAM and Shimano Red 10 to 11-speed wheel conversion can only be completed by an authorized Zipp Service Center Includes cassette spacer 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 Zipp Speed Weaponry Freehub Bodies