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 IS42/28.6|IS52/40 Black 102g 28.6 42/52 39.8 45?/45? 1-1/8` to 1.5`UPC/EAN/GTIN: 616043825816