The PI-1 Alloy 45x45 headset has an aluminum top cap, upper bearing cover, lower race and upper and lower cups. All-aluminum construction results in a lightweight headset. Each headset is fitted with super-smooth rolling, precision, 45x45 angular-contact sealed bearings. Features: Because this versatile headset has 45x45 angular-contact bearings, you can use the included cups and install it in standard frames. Or, leave the cup in the box, and use it as an Integrated headset Specs: Bearing Type45/45 Degree ACB ColorBlack Defined ColorBlack Crown Race26 S.H.I.S LowerEC30 S.H.I.S UpperEC30 S.H.I.S. Stem Clamp Diameter25.4 Threadless