Designed to allow the use of 1-inch forks with frames that have 1 1/8-inch integrated head tubesBox Two Integrated headsets feature an aluminum top cap, CNC-machined bearing cover, and split crown race with super-smooth rolling 45x45 bearingsIS42/25.4|IS42/26.4Black97g25.44226.445°/45°1-1/8` to 1`UPC/EAN/GTIN: 616043826042