Genuine, Cannondale Headset by FSA. Durable angular contact drop-in headset to suit your Cannondale Caad X and Optimo road frames. (and many others). 

• These are sold as pictured
• 45 x 45 degree angular contact, drop in bearings.
• Suitable for frames that are straight 1 1/8" - 1 1/4" steerer.
• Includes bearings, crown race, bearing spacer, alloy FSA topcap