Box components Box Two Integrated Taper Headset IS42/28.6|IS52/40 HeadsetBOX Two Integrated Headset 1. 5" Tapered Black. Box Two Integrated Headsets feature an aluminum top cap CNC machined bearing cover and split crown race with super smooth rolling precision bearings. The 1. 5 inch headset is designed for tapered frames and forks but also includes an adapter which allows you to run a straight 1 1 8 inch fork in a tapered head tube It has a 45x45 degree upper bearing and a 36x45 degree lower bearing CNCd aluminum bearing