Revised for 2007, the Imperator S-Pro headset features 7075-T6 CNC aluminium cups meaning great strength and weight. If you damage the crown race when you are changing forks then it's no problem as we can provide this as a spare part.We've worked hard to develop the seals and bearings on the Imperator S-Pro meaning that you don't need to worry about corrosion regardless of whether you are riding dirt or marathon enduro events. Optimal insertion depth is 12mm. As with all NC-17 headsets, the headset cap, bolt and star fangled nut are all included. 7075-T6 Aluminium CNC-made. German high quality Sealed bearing. 1 1/8" Ahead. Height: 31,2mm.