Booster thru-axle hub spacer kits are designed to give your non-Boost front and rear thru-axle hubs the boost they need to fit any Boost-compatible frame or fork.Kit includes center lock adaptor, allowing riders to use 6-bolt rotors on Shimano Center Lock compatible hubsKit adapts 142 x 12mm rear hub to 148 x 12mmIncludes adapter to 6-bolt rotorsIncludes external spline lock ring for thru-axle compatibilityIncludes two 3mm axle spacersThru-axle not included Problem Solvers Booster Hub Spacing Kit - Rear Rear Axle Conversion Kit UPC: 708752352155