TheShimano Deore M6000 Centre Lock Disc 135mm QR Rear Hubuses a Centre-Lock disc rotor fitting - ideal for Deore hydraulic and mechanical disc brake systems.ThisShimano Deore hub uses angular contact bearings designed to cradle the balls giving both radial and lateral support for superior strength and durability in real world riding conditions; they also offer precision bearing adjustment and easy maintenance. Shimano Deore M6000 Centre Lock Disc 135mm QR Rear Hub Features Low maintenance design includes single contact seals to keep out mud and water Low-friction Cubic Boron Nitride treatment cone race surfaces for smooth action and long bearing life For use in 135 mm dropouts including quick release skewer Internal grease sleeve help maintain and increase service life of hub by holding the grease in the bearing housing