The chris king inset 4 headset the chris king insettrade 4 is designed for 49mm headtubes and 1 18rdquosteerer tubes commonly found on dual crown forks used on downhill and freeride bikes used by the santa cruz syndicate on their world championship winning race bikes this 49mm headset is built to take big hits with out any effect on headset function chris king inset 4 headset features engineered manufactured and assembled in portland oregon usa 10 year built