SHIMANO DEORE - Rear FREEHUB - MICRO SPLINE - CENTER LOCK - Disc Brake - 148x12 mm E-THRU Axle - 12-speed SHIMANO DEORE Rear FREEHUB for Disc Brake 148x12 mm E-THRU 12-speed Simple setup and reliable trail performance Easy disc brake rotor installation with spline mount and lock ring Stiff amp; lightweight 12 mm E-THRU skewer system Labyrinth amp; Contact Sealing More maneuverability and aggressive riding realized Wide 148 mm O.L.D. Smaller spline diameter for 10T top gear