The shimano 105 5800 rear hub is a durable and smooth 9 10 and 11 speed compatible rear hub with an anodised cold forged aluminium hub shell it features cubic boron nitride treated cone races provide a mirror smooth bearing surface for low friction corrosion free performance the labyrinth and low friction contact sealing effectively shuts out water and muck without affecting rotational smoothness an internal grease sleeve helps maintain and increase service life of hub by holding the grease