Freehub body X4 type (R642), Micro Spline, steel 6-pawls, 3xNBK, w/oil seal, water seal, w/distance spacer, with side cap, w/AXLE BOOST 12x148 for XD642SB-B12, XDS642SB-B12, 6-BOLT, OEM - IMPORTANT NOTE: Micro Spline freehub body is compatible only with Micro Spline axle.