The Classic Press Fit upper headset is designed for bikes with semi-integrated ZS headsets and is equipped with fully stainless steel bearings, which are infused with Ritchey grease. Semi-integrated upper headset Classic ZS with polished finish. Material: alloy Stack Height: 10.1mm Headtube ID: 44mm S.H.I.S.: ZS44/28.6 (1 ⅛”) ZS44/28.6 (1 ⅛”) bearing: 41.0/30.15/7mm 45°/45° - sealed cartridge (ACB) Weight: 51g Color: high-polish silver