The Tange-Seiki Passage 1" threaded headset is constructed of steel and features 5/32" ball bearings. FEATURES : Stack height 30.3mm Triple sealed mechanism High-tension steel SPECS : Crown Race: 26/ 27 S.H.I.S. Stem Clamp Diameter: 25.4-24tpi Quill Bearing Type: Cup and Cone S.H.I.S Lower: EC30 S.H.I.S Upper: EC30 Defined Color: Silver Lower Stack Height: 10.3 Weight: 156 Upper Stack Height: 20.3