Fsa is the world leading headset manufacturer and the core of their product line with many years of experience they understand that multiple dimensions and exacting requirements are a must when it comes to headsets the fsa orbit cf 1 18 integrated headset is an integrated headset that is designed to fit campagnolo hiddenset head tubes is a 46mm od it uses 1 18 45 degree angular contact bearings and has a alloy top cap that helps bring the weight down