To suit tapered forks Split type 7075-T6 aluminium crown race for simple, tool free installation Upper cup Stack height: 11mm - Total upper stack height including bearing cover: 16mm Lower cup Stack height: 2.5mm Upper Bearing: 41mm OD, 45 x 45 Degree AC sealed bearing Lower Bearing: 52mm OD, 45 x 45 Degree AC sealed bearing 'SHIS' standard headsets Headset comes complete with top-cap (star-nut included), bearings and crown race - all parts required for fitment Attributes Bearing Grade ACB Sealed Crown Race Diameter 40mm Headset Position Complete Headset Type ZS, External threadless Lower Cup 56mm Material 7075-T6 Aluminum Primary Color Black S.H.I.S. EC44/28.6 | ZS56/40 SHIS Lower ZS56/40 SHIS Upper EC44/28.6 Steerer Tube 1-1/8''-1.5'' Upper Cup 44mm