Pro 5 Freehub Assembly MS - X12 148/157mm.Features:- Micro-Spline aluminum core for Pro 5 hub.- Shimano Micro-Spline 12V print.Specifications:- Weight: 75gIn the box:- Complete with dust seal, bearings, springs, pawls and cup: X12 - wheelbase 12X142mm / 12X148mm / 12X157mm