`- FSA's flagship headsets in separate upper and lower headset cup assemblies\n- Upper assemblies include star nut and top cap, while lower assemblies include crown race\n- FSA Integrated 41.2mm ID (36x45), Campy Hiddenset 42.0mm ID (45x45) , ZS (ZeroStack), or EC (traditional External Cup) available for 1-1/8" and tapered steerers\n- For clarification go to https://www.fsaeasyheadset.com