Odyssey Pro Integrated Headsetmaterial: 6061 T6 Aluminium CNC machined dust cover type: integrated Campy spec 45 45 degree fork size: 1 1 8 inch threadless bearings: high quality sealed bearings additional information: low stack height 45 tapered bearings 41. 8mm outer diameter (fits 42mm bmx head tubes) designed with the lowest possible stack height, using high quality sealed bearings and a precision tapered wedge to keep the headset tight at all times