Shimano ultegra hub front 6800the shimano ultegra series is pro proven as it is a direct trickle down from their dura ace group features improved sealing performance through the use of low friction labyrinth and contact seals and an internal grease sleeve special boron nitride machining process is applied to the cones for super smooth rotation cold forged aluminium hub shell with anodized finish comes complete with quick release skewer seriesultegra materials finishaluminiumanodized fl