Ritchey: The Ritchey External Cup EC Threadless headset features a smaller upper bearing to save weight, while the lightweight, precision-machined aluminum cups are deep for solid insertion. Material: steelThreadlessStack height: 29.8mmStack height upper: 16.8mmStack height lower: 13mmHeadtube ID: 34mmS.H.I.S. upper: EC34/28.6 (1 ?”)S.H.I.S. lower: EC34/30 (1 ?”)Bearings: semi-cartridge (SSC)Top cap includedWeight: 146gColour: black