Ritchey Pro Zero Integrated Headsets. Compatible with frames designed for Campagnolo Hiddenset .CX models have a pivoting housing stop for easier cable routing and low frictionCX models have a 15.3mm top capBlack alloy bearing cover, alloy crown raceStainless steel angular contact bearing packed w/ Ritchey greaseCampagnolo-compatible head tube integrated style, fits 42mm ID head tubes45/45 degree angular contact bearings fit directly into head tubeDesigned for 46mm OD head tubeItem SpecificationsColorBlackWeight85gMaterialAluminumSteerer Tube1-1/8" ThreadlessCrown Race30.0Stack Height16.8mmBearing TypeAngular Contact BearingDefined ColorBlackS.H.I.S UpperIS42S.H.I.S LowerIS42S.H.I.S. Clamp Diameter28.6