Stiff, lightweight 7050 aluminum arms updated with narrower 176mm Q-Factor Revised preload collar without the 2mm hex bolt on earlier collars Futureproof CINCH System allows you to quickly switch out chainrings 136mm wide spindle: 52mm chainline on bikes with Boost 148mm rear spacing 143mm wide spindle: for bikes with Super Boost 157mm rear spacing Backed by a lifetime warranty, includes pedal washers Bottom bracket cups/bearings sold separately 515g (170mm)