Box Two Integrated headsets feature an aluminum top cap, CNC-machined bearing cover, and split crown race with super-smooth rolling, precision 45x45 bearings Box Two Integrated headsets feature an aluminum top cap, CNC-machined bearing cover, and split crown race with super-smooth rolling, precision 45x45 bearings The 1.5` headset is designed solely for tapered frames and forks but also includes an adapter which allows you to run a straight 1 1/8` fork in a tapered head tube