Works Components Angle Headset 1Deg EC44/28.6|ZS56/40 130-139HT BlkTo 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