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 ce plus carbon top cap integrated headset is an integrated headset that is designed to fit campagnolo hiddenset head tubes is a 45mm od it uses 1 18 45 degree angular contact bearings and has a carbon top cap that helps bring the weight down