Shimano FH-MT400B Complete Hub Axle Kit Description: The Shimano FH-MT400B Complete Hub Axle Kit is a factory replacement part. This kit features the hardened steel axle, bearings, and cones needed to rebuild damaged or worn out hub internals, and this axle is designed for a 12x148mm through axle and boost rear hub spacing. Features: Includes one hardened steel rear axle, bearing cones, lock nuts, ball bearings, ball bearing retainer, dust covers, and seal rings Fits Shimano FH-MT400-B 12x148mm thru axle rear hub